644254463442 has 32 divisors (see below), whose sum is σ = 1294150613184. Its totient is φ = 213812019200.

The previous prime is 644254463389. The next prime is 644254463471. The reversal of 644254463442 is 244364452446.

It is a junction number, because it is equal to n+sod(n) for n = 644254463391 and 644254463400.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3108517 + ... + 3309287.

It is an arithmetic number, because the mean of its divisors is an integer number (40442206662).

Almost surely, 2^644254463442 is an apocalyptic number.

644254463442 is an abundant number, since it is smaller than the sum of its proper divisors (649896149742).

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

644254463442 is a wasteful number, since it uses less digits than its factorization.

644254463442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203114.

The product of its digits is 8847360, while the sum is 48.

The spelling of 644254463442 in words is "six hundred forty-four billion, two hundred fifty-four million, four hundred sixty-three thousand, four hundred forty-two".