640560000 has 320 divisors, whose sum is σ = 2265587280. Its totient is φ = 159744000.

The previous prime is 640559993. The next prime is 640560047. The reversal of 640560000 is 65046.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×640560000² = 820634227200000000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4079922 + ... + 4080078.

Almost surely, 2^640560000 is an apocalyptic number.

640560000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640560000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1132793640).

640560000 is an abundant number, since it is smaller than the sum of its proper divisors (1625027280).

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

640560000 is a wasteful number, since it uses less digits than its factorization.

640560000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 640560000 is about 25309.2868330975. The cubic root of 640560000 is about 862.0251534516.

It can be divided in two parts, 6 and 40560000, that multiplied together give a square (243360000 = 15600²).

The spelling of 640560000 in words is "six hundred forty million, five hundred sixty thousand".