645164420 has 24 divisors (see below), whose sum is σ = 1362965184. Its totient is φ = 256519136.

The previous prime is 645164417. The next prime is 645164459. The reversal of 645164420 is 24461546.

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, 93242 + ... + 99921.

It is an arithmetic number, because the mean of its divisors is an integer number (56790216).

Almost surely, 2^645164420 is an apocalyptic number.

It is an amenable number.

645164420 is an abundant number, since it is smaller than the sum of its proper divisors (717800764).

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

645164420 is a wasteful number, since it uses less digits than its factorization.

645164420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193339 (or 193337 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 645164420 is about 25400.0870077250. The cubic root of 645164420 is about 864.0856700173.

The spelling of 645164420 in words is "six hundred forty-five million, one hundred sixty-four thousand, four hundred twenty".