644761167446 has 8 divisors (see below), whose sum is σ = 1055063728584. Its totient is φ = 293073257920.

The previous prime is 644761167397. The next prime is 644761167473.

644761167446 is nontrivially palindromic in base 10.

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

It is a junction number, because it is equal to n+sod(n) for n = 644761167391 and 644761167400.

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 14653662875 + ... + 14653662918.

It is an arithmetic number, because the mean of its divisors is an integer number (131882966073).

Almost surely, 2^644761167446 is an apocalyptic number.

644761167446 is a deficient number, since it is larger than the sum of its proper divisors (410302561138).

644761167446 is a wasteful number, since it uses less digits than its factorization.

644761167446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29307325806.

The product of its digits is 16257024, while the sum is 56.

The spelling of 644761167446 in words is "six hundred forty-four billion, seven hundred sixty-one million, one hundred sixty-seven thousand, four hundred forty-six".