640590494400 has 252 divisors, whose sum is σ = 2332343965224. Its totient is φ = 166657536000.

The previous prime is 640590494393. The next prime is 640590494419. The reversal of 640590494400 is 4494095046.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 47895 + ... + 1132905.

Almost surely, 2^640590494400 is an apocalyptic number.

640590494400 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 640590494400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1166171982612).

640590494400 is an abundant number, since it is smaller than the sum of its proper divisors (1691753470824).

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

640590494400 is a wasteful number, since it uses less digits than its factorization.

640590494400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1085080 (or 1085062 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 640590494400 in words is "six hundred forty billion, five hundred ninety million, four hundred ninety-four thousand, four hundred".