645615403232 has 72 divisors (see below), whose sum is σ = 1306256087808. Its totient is φ = 314102036480.

The previous prime is 645615403217. The next prime is 645615403243. The reversal of 645615403232 is 232304516546.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a self number, because there is not a number n which added to its sum of digits gives 645615403232.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20586668 + ... + 20618004.

It is an arithmetic number, because the mean of its divisors is an integer number (18142445664).

Almost surely, 2^645615403232 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 645615403232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (653128043904).

645615403232 is an abundant number, since it is smaller than the sum of its proper divisors (660640684576).

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

645615403232 is a wasteful number, since it uses less digits than its factorization.

645615403232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31812 (or 31763 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 41.

Adding to 645615403232 its reverse (232304516546), we get a palindrome (877919919778).

The spelling of 645615403232 in words is "six hundred forty-five billion, six hundred fifteen million, four hundred three thousand, two hundred thirty-two".