645233620 has 24 divisors (see below), whose sum is σ = 1361808000. Its totient is φ = 256794912.

The previous prime is 645233609. The next prime is 645233671. The reversal of 645233620 is 26332546.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77080 + ... + 85039.

It is an arithmetic number, because the mean of its divisors is an integer number (56742000).

Almost surely, 2^645233620 is an apocalyptic number.

It is an amenable number.

645233620 is an abundant number, since it is smaller than the sum of its proper divisors (716574380).

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

645233620 is a wasteful number, since it uses less digits than its factorization.

645233620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162327 (or 162325 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 31.

The square root of 645233620 is about 25401.4491712579. The cubic root of 645233620 is about 864.1165627060.

The spelling of 645233620 in words is "six hundred forty-five million, two hundred thirty-three thousand, six hundred twenty".