644454546 has 16 divisors (see below), whose sum is σ = 1289200224. Its totient is φ = 214769664.

The previous prime is 644454533. The next prime is 644454563. The reversal of 644454546 is 645454446.

It is a super-2 number, since 2×644454546² = 830643323720132232, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 644454498 and 644454507.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25746 + ... + 44178.

It is an arithmetic number, because the mean of its divisors is an integer number (80575014).

Almost surely, 2^644454546 is an apocalyptic number.

644454546 is an abundant number, since it is smaller than the sum of its proper divisors (644745678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644454546 is a wasteful number, since it uses less digits than its factorization.

644454546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24265.

The product of its digits is 921600, while the sum is 42.

The square root of 644454546 is about 25386.1093119840. The cubic root of 644454546 is about 863.7686360742.

The spelling of 644454546 in words is "six hundred forty-four million, four hundred fifty-four thousand, five hundred forty-six".