644026467 has 16 divisors (see below), whose sum is σ = 985704192. Its totient is φ = 366391200.

The previous prime is 644026459. The next prime is 644026499. The reversal of 644026467 is 764620446.

It is not a de Polignac number, because 644026467 - 2³ = 644026459 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644026567) 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, 62784 + ... + 72317.

It is an arithmetic number, because the mean of its divisors is an integer number (61606512).

Almost surely, 2^644026467 is an apocalyptic number.

644026467 is a deficient number, since it is larger than the sum of its proper divisors (341677725).

644026467 is a wasteful number, since it uses less digits than its factorization.

644026467 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135338.

The product of its (nonzero) digits is 193536, while the sum is 39.

The square root of 644026467 is about 25377.6765484943. The cubic root of 644026467 is about 863.5773409095.

The spelling of 644026467 in words is "six hundred forty-four million, twenty-six thousand, four hundred sixty-seven".