665652256566 has 16 divisors (see below), whose sum is σ = 1452332196288. Its totient is φ = 201712805000.

The previous prime is 665652256553. The next prime is 665652256571.

665652256566 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×665652256566² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5042820060 + ... + 5042820191.

It is an arithmetic number, because the mean of its divisors is an integer number (90770762268).

Almost surely, 2^665652256566 is an apocalyptic number.

665652256566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

665652256566 is an abundant number, since it is smaller than the sum of its proper divisors (786679939722).

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

665652256566 is a wasteful number, since it uses less digits than its factorization.

665652256566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10085640267.

The product of its digits is 116640000, while the sum is 60.

The spelling of 665652256566 in words is "six hundred sixty-five billion, six hundred fifty-two million, two hundred fifty-six thousand, five hundred sixty-six".