644446742016 has 160 divisors (see below), whose sum is σ = 2140484214528. Its totient is φ = 167388733440.

The previous prime is 644446741997. The next prime is 644446742047. The reversal of 644446742016 is 610247644446.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

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, 2606155 + ... + 2842698.

Almost surely, 2^644446742016 is an apocalyptic number.

644446742016 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

644446742016 is an abundant number, since it is smaller than the sum of its proper divisors (1496037472512).

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

644446742016 is a wasteful number, since it uses less digits than its factorization.

644446742016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5448892 (or 5448876 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 48.

The spelling of 644446742016 in words is "six hundred forty-four billion, four hundred forty-six million, seven hundred forty-two thousand, sixteen".