640762844400 has 600 divisors, whose sum is σ = 2631306934784. Its totient is φ = 146285222400.

The previous prime is 640762844339. The next prime is 640762844401. The reversal of 640762844400 is 4448267046.

640762844400 is a `hidden beast` number, since 64 + 0 + 76 + 2 + 84 + 440 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (600).

It is a super-2 number, since 2×640762844400² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640762844401) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 349951485 + ... + 349953315.

Almost surely, 2^640762844400 is an apocalyptic number.

640762844400 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 640762844400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1315653467392).

640762844400 is an abundant number, since it is smaller than the sum of its proper divisors (1990544090384).

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

640762844400 is a wasteful number, since it uses less digits than its factorization.

640762844400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3411 (or 3391 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 45.

The spelling of 640762844400 in words is "six hundred forty billion, seven hundred sixty-two million, eight hundred forty-four thousand, four hundred".