644406554463296 has 14 divisors (see below), whose sum is σ = 1278744256513230. Its totient is φ = 322203277231616.

The previous prime is 644406554463271. The next prime is 644406554463367. The reversal of 644406554463296 is 692364455604446.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 642842354000896 + 1564200462400 = 25354336^2 + 1250680^2 .

It is a super-2 number, since 2×644406554463296² (a number of 30 digits) contains 22 as substring.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5034426206681 + ... + 5034426206808.

Almost surely, 2^{644406554463296} is an apocalyptic number.

It is an amenable number.

644406554463296 is a deficient number, since it is larger than the sum of its proper divisors (634337702049934).

644406554463296 is a wasteful number, since it uses less digits than its factorization.

644406554463296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10068852413501 (or 10068852413491 counting only the distinct ones).

The product of its (nonzero) digits is 1791590400, while the sum is 68.

The spelling of 644406554463296 in words is "six hundred forty-four trillion, four hundred six billion, five hundred fifty-four million, four hundred sixty-three thousand, two hundred ninety-six".