644888145 has 64 divisors (see below), whose sum is σ = 1186099200. Its totient is φ = 296144640.

The previous prime is 644888143. The next prime is 644888173. The reversal of 644888145 is 541888446.

It is a happy number.

It is not a de Polignac number, because 644888145 - 2¹ = 644888143 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644888094 and 644888103.

It is not an unprimeable number, because it can be changed into a prime (644888143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 412876 + ... + 414434.

It is an arithmetic number, because the mean of its divisors is an integer number (18532800).

Almost surely, 2^644888145 is an apocalyptic number.

It is an amenable number.

644888145 is a deficient number, since it is larger than the sum of its proper divisors (541211055).

644888145 is a wasteful number, since it uses less digits than its factorization.

644888145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1710.

The product of its digits is 983040, while the sum is 48.

The square root of 644888145 is about 25394.6479597572. The cubic root of 644888145 is about 863.9623116169.

The spelling of 644888145 in words is "six hundred forty-four million, eight hundred eighty-eight thousand, one hundred forty-five".