644506269 has 16 divisors (see below), whose sum is σ = 950309184. Its totient is φ = 385257600.

The previous prime is 644506241. The next prime is 644506271. The reversal of 644506269 is 962605446.

644506269 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644506269 - 2⁷ = 644506141 is a prime.

It is a super-2 number, since 2×644506269² = 830776661560600722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 644506269.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644506229) 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, 131362 + ... + 136179.

It is an arithmetic number, because the mean of its divisors is an integer number (59394324).

Almost surely, 2^644506269 is an apocalyptic number.

It is an amenable number.

644506269 is a deficient number, since it is larger than the sum of its proper divisors (305802915).

644506269 is a wasteful number, since it uses less digits than its factorization.

644506269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267628.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 644506269 is about 25387.1280179543. The cubic root of 644506269 is about 863.7917437344.

The spelling of 644506269 in words is "six hundred forty-four million, five hundred six thousand, two hundred sixty-nine".