640401562320 has 160 divisors (see below), whose sum is σ = 2140123689984. Its totient is φ = 157477478400.

The previous prime is 640401562309. The next prime is 640401562331. The reversal of 640401562320 is 23265104046.

It is an interprime number because it is at equal distance from previous prime (640401562309) and next prime (640401562331).

It is a super-2 number, since 2×640401562320² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2988360 + ... + 3195480.

Almost surely, 2^640401562320 is an apocalyptic number.

640401562320 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 640401562320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1070061844992).

640401562320 is an abundant number, since it is smaller than the sum of its proper divisors (1499722127664).

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

640401562320 is a wasteful number, since it uses less digits than its factorization.

640401562320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208141 (or 208135 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

Adding to 640401562320 its reverse (23265104046), we get a palindrome (663666666366).

The spelling of 640401562320 in words is "six hundred forty billion, four hundred one million, five hundred sixty-two thousand, three hundred twenty".