644473467 has 36 divisors (see below), whose sum is σ = 1058562960. Its totient is φ = 377102880.

The previous prime is 644473457. The next prime is 644473471. The reversal of 644473467 is 764374446.

It is not a de Polignac number, because 644473467 - 2⁷ = 644473339 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644473457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 21378 + ... + 41784.

Almost surely, 2^644473467 is an apocalyptic number.

644473467 is a deficient number, since it is larger than the sum of its proper divisors (414089493).

644473467 is a wasteful number, since it uses less digits than its factorization.

644473467 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20464 (or 20450 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 45.

The square root of 644473467 is about 25386.4819736804. The cubic root of 644473467 is about 863.7770893243. Note that the first 3 decimals are identical.

The spelling of 644473467 in words is "six hundred forty-four million, four hundred seventy-three thousand, four hundred sixty-seven".