640322431632 has 240 divisors, whose sum is σ = 1994245574400. Its totient is φ = 196623797760.

The previous prime is 640322431627. The next prime is 640322431633. The reversal of 640322431632 is 236134223046.

640322431632 is a `hidden beast` number, since 6 + 403 + 2 + 243 + 1 + 6 + 3 + 2 = 666.

It is a super-2 number, since 2×640322431632² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (640322431633) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 37152457 + ... + 37169687.

It is an arithmetic number, because the mean of its divisors is an integer number (8309356560).

Almost surely, 2^640322431632 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640322431632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997122787200).

640322431632 is an abundant number, since it is smaller than the sum of its proper divisors (1353923142768).

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

640322431632 is a wasteful number, since it uses less digits than its factorization.

640322431632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17783 (or 17758 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 36.

Adding to 640322431632 its reverse (236134223046), we get a palindrome (876456654678).

It can be divided in two parts, 6403224 and 31632, that added together give a cube (6434856 = 186³).

The spelling of 640322431632 in words is "six hundred forty billion, three hundred twenty-two million, four hundred thirty-one thousand, six hundred thirty-two".