665727276564 has 144 divisors (see below), whose sum is σ = 1942185423360. Its totient is φ = 188334720000.

The previous prime is 665727276553. The next prime is 665727276587. The reversal of 665727276564 is 465672727566.

It is a happy number.

665727276564 is a `hidden beast` number, since 6 + 6 + 572 + 7 + 2 + 7 + 6 + 56 + 4 = 666.

It is a super-2 number, since 2×665727276564² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29575314 + ... + 29597814.

Almost surely, 2^665727276564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665727276564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (971092711680).

665727276564 is an abundant number, since it is smaller than the sum of its proper divisors (1276458146796).

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

665727276564 is a wasteful number, since it uses less digits than its factorization.

665727276564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23670 (or 23665 counting only the distinct ones).

The product of its digits is 177811200, while the sum is 63.

The spelling of 665727276564 in words is "six hundred sixty-five billion, seven hundred twenty-seven million, two hundred seventy-six thousand, five hundred sixty-four".