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640000000000 = 216510
BaseRepresentation
bin10010101000000101111…
…10010000000000000000
32021011221200220120222201
421110002332100000000
540441210000000000
61210002325042544
764144540145554
oct11240276200000
92234850816881
10640000000000
11227471351639
12a4052856454
1348475a0ca6a
1422d94851864
15119ab85496a
hex9502f90000

640000000000 has 187 divisors, whose sum is σ = 1599987760201. Its totient is φ = 256000000000.

The previous prime is 639999999979. The next prime is 640000000007. The reversal of 640000000000 is 46.

The square root of 640000000000 is 800000.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 5 ways, for example, as 3681091584 + 636318908416 = 60672^2 + 797696^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (640000000007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 10 ways as a sum of consecutive naturals, for example, 127999999998 + ... + 128000000002.

Almost surely, 2640000000000 is an apocalyptic number.

640000000000 is the 800000-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640000000000

640000000000 is an abundant number, since it is smaller than the sum of its proper divisors (959987760201).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640000000000 is an frugal number, since it uses more digits than its factorization.

640000000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 7 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

640000000000 divided by its sum of digits (10) gives a cube (64000000000 = 40003).

Adding to 640000000000 its reverse (46), we get a palindrome (640000000046).

The spelling of 640000000000 in words is "six hundred forty billion", and thus it is an aban number.