644235105 has 16 divisors (see below), whose sum is σ = 1032356160. Its totient is φ = 343065408.

The previous prime is 644235079. The next prime is 644235107. The reversal of 644235105 is 501532446.

It is not a de Polignac number, because 644235105 - 2⁶ = 644235041 is a prime.

It is a super-2 number, since 2×644235105² = 830077741028722050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (644235107) 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, 22702 + ... + 42471.

It is an arithmetic number, because the mean of its divisors is an integer number (64522260).

Almost surely, 2^644235105 is an apocalyptic number.

It is an amenable number.

644235105 is a deficient number, since it is larger than the sum of its proper divisors (388121055).

644235105 is a wasteful number, since it uses less digits than its factorization.

644235105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65840.

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 644235105 is about 25381.7868756319. The cubic root of 644235105 is about 863.6705853156.

The spelling of 644235105 in words is "six hundred forty-four million, two hundred thirty-five thousand, one hundred five".