645993132 has 48 divisors (see below), whose sum is σ = 1597835232. Its totient is φ = 202429440.

The previous prime is 645993113. The next prime is 645993143. The reversal of 645993132 is 231399546.

It is a happy number.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 280578 + ... + 282870.

It is an arithmetic number, because the mean of its divisors is an integer number (33288234).

Almost surely, 2^645993132 is an apocalyptic number.

It is an amenable number.

645993132 is an abundant number, since it is smaller than the sum of its proper divisors (951842100).

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

645993132 is a wasteful number, since it uses less digits than its factorization.

645993132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3698 (or 3696 counting only the distinct ones).

The product of its digits is 174960, while the sum is 42.

The square root of 645993132 is about 25416.3949449956. The cubic root of 645993132 is about 864.4554836442.

The spelling of 645993132 in words is "six hundred forty-five million, nine hundred ninety-three thousand, one hundred thirty-two".