644136686631446 has 8 divisors (see below), whose sum is σ = 966206434723824. Its totient is φ = 322067875056840.

The previous prime is 644136686631413. The next prime is 644136686631457.

644136686631446 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 232407410 + ... + 235162661.

It is an arithmetic number, because the mean of its divisors is an integer number (120775804340478).

Almost surely, 2^{644136686631446} is an apocalyptic number.

644136686631446 is a deficient number, since it is larger than the sum of its proper divisors (322069748092378).

644136686631446 is a wasteful number, since it uses less digits than its factorization.

644136686631446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468258886.

The product of its digits is 859963392, while the sum is 68.

The spelling of 644136686631446 in words is "six hundred forty-four trillion, one hundred thirty-six billion, six hundred eighty-six million, six hundred thirty-one thousand, four hundred forty-six".