644462654 has 16 divisors (see below), whose sum is σ = 1055327616. Its totient is φ = 292728600.

The previous prime is 644462647. The next prime is 644462671. The reversal of 644462654 is 456264446.

It is a super-2 number, since 2×644462654² = 830664224801447432, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23549 + ... + 42935.

It is an arithmetic number, because the mean of its divisors is an integer number (65957976).

Almost surely, 2^644462654 is an apocalyptic number.

644462654 is a deficient number, since it is larger than the sum of its proper divisors (410864962).

644462654 is a wasteful number, since it uses less digits than its factorization.

644462654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20911.

The product of its digits is 552960, while the sum is 41.

The square root of 644462654 is about 25386.2690051138. The cubic root of 644462654 is about 863.7722584692.

The spelling of 644462654 in words is "six hundred forty-four million, four hundred sixty-two thousand, six hundred fifty-four".