6640392994816 has 171 divisors, whose sum is σ = 15470564851479. Its totient is φ = 2841924599808.

The previous prime is 6640392994813. The next prime is 6640392994841. The reversal of 6640392994816 is 6184992930466.

The square root of 6640392994816 is 2576896.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640392994811) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 9235594905 + ... + 9235595623.

Almost surely, 2^{6640392994816} is an apocalyptic number.

6640392994816 is the 2576896-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6640392994816

6640392994816 is an abundant number, since it is smaller than the sum of its proper divisors (8830171856663).

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

6640392994816 is an frugal number, since it uses more digits than its factorization.

6640392994816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1488 (or 728 counting only the distinct ones).

The product of its (nonzero) digits is 120932352, while the sum is 67.

The spelling of 6640392994816 in words is "six trillion, six hundred forty billion, three hundred ninety-two million, nine hundred ninety-four thousand, eight hundred sixteen".