640162598400 has 720 divisors, whose sum is σ = 2546964900480. Its totient is φ = 152484249600.

The previous prime is 640162598377. The next prime is 640162598443. The reversal of 640162598400 is 4895261046.

640162598400 is a `hidden beast` number, since 6 + 4 + 0 + 16 + 2 + 598 + 40 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 46418706 + ... + 46432494.

Almost surely, 2^640162598400 is an apocalyptic number.

640162598400 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 640162598400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1273482450240).

640162598400 is an abundant number, since it is smaller than the sum of its proper divisors (1906802302080).

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

640162598400 is a wasteful number, since it uses less digits than its factorization.

640162598400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13867 (or 13843 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 640162598400 in words is "six hundred forty billion, one hundred sixty-two million, five hundred ninety-eight thousand, four hundred".