644535564442 has 96 divisors (see below), whose sum is σ = 1230566867712. Its totient is φ = 247811520000.

The previous prime is 644535564401. The next prime is 644535564457. The reversal of 644535564442 is 244465535446.

It is a self number, because there is not a number n which added to its sum of digits gives 644535564442.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 53204178 + ... + 53216290.

It is an arithmetic number, because the mean of its divisors is an integer number (12818404872).

Almost surely, 2^644535564442 is an apocalyptic number.

644535564442 is a deficient number, since it is larger than the sum of its proper divisors (586031303270).

644535564442 is a wasteful number, since it uses less digits than its factorization.

644535564442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12556 (or 12545 counting only the distinct ones).

The product of its digits is 27648000, while the sum is 52.

The spelling of 644535564442 in words is "six hundred forty-four billion, five hundred thirty-five million, five hundred sixty-four thousand, four hundred forty-two".