644566662016254 has 24 divisors (see below), whose sum is σ = 1400366444649120. Its totient is φ = 214270116526368.

The previous prime is 644566662016229. The next prime is 644566662016261. The reversal of 644566662016254 is 452610266665446.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 644566662016191 and 644566662016200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48786449799 + ... + 48786463010.

It is an arithmetic number, because the mean of its divisors is an integer number (58348601860380).

Almost surely, 2^{644566662016254} is an apocalyptic number.

644566662016254 is an abundant number, since it is smaller than the sum of its proper divisors (755799782632866).

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

644566662016254 is a wasteful number, since it uses less digits than its factorization.

644566662016254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97572913184 (or 97572913181 counting only the distinct ones).

The product of its (nonzero) digits is 298598400, while the sum is 63.

The spelling of 644566662016254 in words is "six hundred forty-four trillion, five hundred sixty-six billion, six hundred sixty-two million, sixteen thousand, two hundred fifty-four".