66565256566 has 4 divisors (see below), whose sum is σ = 99847884852. Its totient is φ = 33282628282.

The previous prime is 66565256557. The next prime is 66565256573.

It is a happy number.

66565256566 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×66565256566² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66565256566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16641314140 + ... + 16641314143.

It is an arithmetic number, because the mean of its divisors is an integer number (24961971213).

Almost surely, 2^66565256566 is an apocalyptic number.

66565256566 is a deficient number, since it is larger than the sum of its proper divisors (33282628286).

66565256566 is a wasteful number, since it uses less digits than its factorization.

66565256566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33282628285.

The product of its digits is 58320000, while the sum is 58.

The spelling of 66565256566 in words is "sixty-six billion, five hundred sixty-five million, two hundred fifty-six thousand, five hundred sixty-six".