644004962541999 has 12 divisors (see below), whose sum is σ = 943331212738512. Its totient is φ = 423289646740800.

The previous prime is 644004962541989. The next prime is 644004962542009. The reversal of 644004962541999 is 999145269400446.

It is a happy number.

644004962541999 is a `hidden beast` number, since 6 + 4 + 4 + 0 + 0 + 496 + 2 + 5 + 41 + 9 + 99 = 666.

It is an interprime number because it is at equal distance from previous prime (644004962541989) and next prime (644004962542009).

It is not a de Polignac number, because 644004962541999 - 2⁴⁷ = 503267474186671 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644004962541989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 503916245482 + ... + 503916246759.

It is an arithmetic number, because the mean of its divisors is an integer number (78610934394876).

Almost surely, 2^{644004962541999} is an apocalyptic number.

644004962541999 is a deficient number, since it is larger than the sum of its proper divisors (299326250196513).

644004962541999 is a wasteful number, since it uses less digits than its factorization.

644004962541999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007832492318 (or 1007832492315 counting only the distinct ones).

The product of its (nonzero) digits is 604661760, while the sum is 72.

The spelling of 644004962541999 in words is "six hundred forty-four trillion, four billion, nine hundred sixty-two million, five hundred forty-one thousand, nine hundred ninety-nine".