644676676446 has 64 divisors (see below), whose sum is σ = 1529558173440. Its totient is φ = 178895669760.

The previous prime is 644676676367. The next prime is 644676676453.

644676676446 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7723056 + ... + 7806083.

It is an arithmetic number, because the mean of its divisors is an integer number (23899346460).

Almost surely, 2^644676676446 is an apocalyptic number.

644676676446 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

644676676446 is an abundant number, since it is smaller than the sum of its proper divisors (884881496994).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644676676446 is a wasteful number, since it uses less digits than its factorization.

644676676446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15529209.

The product of its digits is 585252864, while the sum is 66.

The spelling of 644676676446 in words is "six hundred forty-four billion, six hundred seventy-six million, six hundred seventy-six thousand, four hundred forty-six".