665464727084544 has 100 divisors (see below), whose sum is σ = 1986236986830624. Its totient is φ = 221821575681024.

The previous prime is 665464727084453. The next prime is 665464727084551. The reversal of 665464727084544 is 445480727464566.

It is a happy number.

665464727084544 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 6 + 4 + 7 + 2 + 70 + 8 + 4 + 544 = 666.

It is a super-2 number, since 2×665464727084544² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8023018992 + ... + 8023101935.

Almost surely, 2^{665464727084544} is an apocalyptic number.

665464727084544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

665464727084544 is an abundant number, since it is smaller than the sum of its proper divisors (1320772259746080).

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

665464727084544 is an equidigital number, since it uses as much as digits as its factorization.

665464727084544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16046120957 (or 16046120932 counting only the distinct ones).

The product of its (nonzero) digits is 4335206400, while the sum is 72.

The spelling of 665464727084544 in words is "six hundred sixty-five trillion, four hundred sixty-four billion, seven hundred twenty-seven million, eighty-four thousand, five hundred forty-four".