645651516 has 24 divisors (see below), whose sum is σ = 1525592320. Its totient is φ = 212492592.

The previous prime is 645651509. The next prime is 645651529. The reversal of 645651516 is 615156546.

It is a super-2 number, since 2×645651516² = 833731760226196512, which contains 22 as substring.

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, 339586 + ... + 341481.

Almost surely, 2^645651516 is an apocalyptic number.

It is an amenable number.

645651516 is an abundant number, since it is smaller than the sum of its proper divisors (879940804).

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

645651516 is a wasteful number, since it uses less digits than its factorization.

645651516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681153 (or 681151 counting only the distinct ones).

The product of its digits is 108000, while the sum is 39.

The square root of 645651516 is about 25409.6736696873. The cubic root of 645651516 is about 864.3030754729.

The spelling of 645651516 in words is "six hundred forty-five million, six hundred fifty-one thousand, five hundred sixteen".