644566046023 has 2 divisors, whose sum is σ = 644566046024. Its totient is φ = 644566046022.

The previous prime is 644566045987. The next prime is 644566046027. The reversal of 644566046023 is 320640665446.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644566046023 - 2²⁵ = 644532491591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644566046027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322283023011 + 322283023012.

It is an arithmetic number, because the mean of its divisors is an integer number (322283023012).

Almost surely, 2^644566046023 is an apocalyptic number.

644566046023 is a deficient number, since it is larger than the sum of its proper divisors (1).

644566046023 is an equidigital number, since it uses as much as digits as its factorization.

644566046023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2488320, while the sum is 46.

The spelling of 644566046023 in words is "six hundred forty-four billion, five hundred sixty-six million, forty-six thousand, twenty-three".