644776363965 has 32 divisors (see below), whose sum is σ = 1076904400896. Its totient is φ = 328804660800.

The previous prime is 644776363961. The next prime is 644776363981. The reversal of 644776363965 is 569363677446.

It is not a de Polignac number, because 644776363965 - 2² = 644776363961 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644776363896 and 644776363905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644776363961) 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 31 ways as a sum of consecutive naturals, for example, 560190 + ... + 1266240.

It is an arithmetic number, because the mean of its divisors is an integer number (33653262528).

Almost surely, 2^644776363965 is an apocalyptic number.

It is an amenable number.

644776363965 is a deficient number, since it is larger than the sum of its proper divisors (432128036931).

644776363965 is a wasteful number, since it uses less digits than its factorization.

644776363965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708729.

The product of its digits is 411505920, while the sum is 66.

The spelling of 644776363965 in words is "six hundred forty-four billion, seven hundred seventy-six million, three hundred sixty-three thousand, nine hundred sixty-five".