640951957800 has 1536 divisors, whose sum is σ = 2840532480000. Its totient is φ = 131681894400.

The previous prime is 640951957787. The next prime is 640951957823. The reversal of 640951957800 is 8759159046.

640951957800 is a `hidden beast` number, since 6 + 40 + 9 + 519 + 5 + 7 + 80 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 3320994504 + ... + 3320994696.

It is an arithmetic number, because the mean of its divisors is an integer number (1849305000).

Almost surely, 2^640951957800 is an apocalyptic number.

640951957800 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 640951957800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1420266240000).

640951957800 is an abundant number, since it is smaller than the sum of its proper divisors (2199580522200).

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

640951957800 is a wasteful number, since it uses less digits than its factorization.

640951957800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413 (or 384 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 640951957800 in words is "six hundred forty billion, nine hundred fifty-one million, nine hundred fifty-seven thousand, eight hundred".