644462441763 has 16 divisors (see below), whose sum is σ = 988628870400. Its totient is φ = 365792678496.

The previous prime is 644462441731. The next prime is 644462441797. The reversal of 644462441763 is 367144264446.

It is not a de Polignac number, because 644462441763 - 2⁵ = 644462441731 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644462441723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102979045 + ... + 102985302.

It is an arithmetic number, because the mean of its divisors is an integer number (61789304400).

Almost surely, 2^644462441763 is an apocalyptic number.

644462441763 is a deficient number, since it is larger than the sum of its proper divisors (344166428637).

644462441763 is a wasteful number, since it uses less digits than its factorization.

644462441763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205964506.

The product of its digits is 9289728, while the sum is 51.

The spelling of 644462441763 in words is "six hundred forty-four billion, four hundred sixty-two million, four hundred forty-one thousand, seven hundred sixty-three".