669864365646 has 64 divisors (see below), whose sum is σ = 1539528227328. Its totient is φ = 190339227648.

The previous prime is 669864365567. The next prime is 669864365657. The reversal of 669864365646 is 646563468966.

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, 30735165 + ... + 30756951.

It is an arithmetic number, because the mean of its divisors is an integer number (24055128552).

Almost surely, 2^669864365646 is an apocalyptic number.

669864365646 is an abundant number, since it is smaller than the sum of its proper divisors (869663861682).

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

669864365646 is a wasteful number, since it uses less digits than its factorization.

669864365646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25785.

The product of its digits is 806215680, while the sum is 69.

The spelling of 669864365646 in words is "six hundred sixty-nine billion, eight hundred sixty-four million, three hundred sixty-five thousand, six hundred forty-six".