663669091686 has 64 divisors (see below), whose sum is σ = 1442246065920. Its totient is φ = 202880039040.

The previous prime is 663669091621. The next prime is 663669091711. The reversal of 663669091686 is 686190966366.

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 31 ways as a sum of consecutive naturals, for example, 431601 + ... + 1230291.

It is an arithmetic number, because the mean of its divisors is an integer number (22535094780).

Almost surely, 2^663669091686 is an apocalyptic number.

663669091686 is an abundant number, since it is smaller than the sum of its proper divisors (778576974234).

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

663669091686 is a wasteful number, since it uses less digits than its factorization.

663669091686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798949.

The product of its (nonzero) digits is 90699264, while the sum is 66.

The spelling of 663669091686 in words is "six hundred sixty-three billion, six hundred sixty-nine million, ninety-one thousand, six hundred eighty-six".