644652051 has 16 divisors (see below), whose sum is σ = 871247520. Its totient is φ = 423947520.

The previous prime is 644652023. The next prime is 644652059. The reversal of 644652051 is 150256446.

It is not a de Polignac number, because 644652051 - 2⁷ = 644651923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644652059) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71961 + ... + 80421.

It is an arithmetic number, because the mean of its divisors is an integer number (54452970).

Almost surely, 2^644652051 is an apocalyptic number.

644652051 is a deficient number, since it is larger than the sum of its proper divisors (226595469).

644652051 is a wasteful number, since it uses less digits than its factorization.

644652051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8806.

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 644652051 is about 25389.9990350532. Note that the first 3 decimals coincide. The cubic root of 644652051 is about 863.8568663462.

The spelling of 644652051 in words is "six hundred forty-four million, six hundred fifty-two thousand, fifty-one".