645169716 has 72 divisors (see below), whose sum is σ = 1652381640. Its totient is φ = 212238336.

The previous prime is 645169709. The next prime is 645169753. The reversal of 645169716 is 617961546.

645169716 is a `hidden beast` number, since 64 + 516 + 9 + 71 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 418366116 + 226803600 = 20454^2 + 15060^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1267270 + ... + 1267778.

It is an arithmetic number, because the mean of its divisors is an integer number (22949745).

Almost surely, 2^645169716 is an apocalyptic number.

It is an amenable number.

645169716 is an abundant number, since it is smaller than the sum of its proper divisors (1007211924).

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

645169716 is a wasteful number, since it uses less digits than its factorization.

645169716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913 (or 908 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 645169716 is about 25400.1912591224. The cubic root of 645169716 is about 864.0880343682.

It can be divided in two parts, 6451 and 69716, that added together give a palindrome (76167).

The spelling of 645169716 in words is "six hundred forty-five million, one hundred sixty-nine thousand, seven hundred sixteen".