646440044646 has 64 divisors (see below), whose sum is σ = 1495261034496. Its totient is φ = 184448275200.

The previous prime is 646440044633. The next prime is 646440044651.

646440044646 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 646440044595 and 646440044604.

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, 4193935 + ... + 4345338.

It is an arithmetic number, because the mean of its divisors is an integer number (23363453664).

Almost surely, 2^646440044646 is an apocalyptic number.

646440044646 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

646440044646 is an abundant number, since it is smaller than the sum of its proper divisors (848820989850).

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

646440044646 is a wasteful number, since it uses less digits than its factorization.

646440044646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8539357.

The product of its (nonzero) digits is 5308416, while the sum is 48.

The spelling of 646440044646 in words is "six hundred forty-six billion, four hundred forty million, forty-four thousand, six hundred forty-six".