640223040 has 112 divisors (see below), whose sum is σ = 2071225728. Its totient is φ = 167491584.

The previous prime is 640223029. The next prime is 640223047. The reversal of 640223040 is 40322046.

It is a junction number, because it is equal to n+sod(n) for n = 640222998 and 640223016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640223047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44589 + ... + 57171.

Almost surely, 2^640223040 is an apocalyptic number.

640223040 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 640223040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1035612864).

640223040 is an abundant number, since it is smaller than the sum of its proper divisors (1431002688).

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

640223040 is a wasteful number, since it uses less digits than its factorization.

640223040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12656 (or 12646 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 640223040 is about 25302.6291124065. The cubic root of 640223040 is about 861.8739737842.

Adding to 640223040 its reverse (40322046), we get a palindrome (680545086).

The spelling of 640223040 in words is "six hundred forty million, two hundred twenty-three thousand, forty".