644254677 has 12 divisors (see below), whose sum is σ = 1015189344. Its totient is φ = 390457320.

The previous prime is 644254673. The next prime is 644254687. The reversal of 644254677 is 776452446.

644254677 is a `hidden beast` number, since 64 + 42 + 546 + 7 + 7 = 666.

It is not a de Polignac number, because 644254677 - 2² = 644254673 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644254673) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3253713 + ... + 3253910.

It is an arithmetic number, because the mean of its divisors is an integer number (84599112).

Almost surely, 2^644254677 is an apocalyptic number.

It is an amenable number.

644254677 is a deficient number, since it is larger than the sum of its proper divisors (370934667).

644254677 is a wasteful number, since it uses less digits than its factorization.

644254677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6507640 (or 6507637 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 45.

The square root of 644254677 is about 25382.1724247551. The cubic root of 644254677 is about 863.6793313927.

The spelling of 644254677 in words is "six hundred forty-four million, two hundred fifty-four thousand, six hundred seventy-seven".