645836432 has 20 divisors (see below), whose sum is σ = 1252755756. Its totient is φ = 322544640.

The previous prime is 645836413. The next prime is 645836437. The reversal of 645836432 is 234638546.

It can be written as a sum of positive squares in 2 ways, for example, as 353289616 + 292546816 = 18796^2 + 17104^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 645836432.

It is not an unprimeable number, because it can be changed into a prime (645836437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8813 + ... + 37004.

Almost surely, 2^645836432 is an apocalyptic number.

It is an amenable number.

645836432 is a deficient number, since it is larger than the sum of its proper divisors (606919324).

645836432 is a wasteful number, since it uses less digits than its factorization.

645836432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46706 (or 46700 counting only the distinct ones).

The product of its digits is 414720, while the sum is 41.

The square root of 645836432 is about 25413.3121021247. The cubic root of 645836432 is about 864.3855803578.

The spelling of 645836432 in words is "six hundred forty-five million, eight hundred thirty-six thousand, four hundred thirty-two".