66116570521 has 32 divisors (see below), whose sum is σ = 70476231168. Its totient is φ = 61950120960.

The previous prime is 66116570503. The next prime is 66116570537. The reversal of 66116570521 is 12507561166.

It is not a de Polignac number, because 66116570521 - 2⁷ = 66116570393 is a prime.

It is a super-2 number, since 2×66116570521² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66116570551) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25109421 + ... + 25112053.

It is an arithmetic number, because the mean of its divisors is an integer number (2202382224).

Almost surely, 2^66116570521 is an apocalyptic number.

It is an amenable number.

66116570521 is a deficient number, since it is larger than the sum of its proper divisors (4359660647).

66116570521 is a wasteful number, since it uses less digits than its factorization.

66116570521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2961.

The product of its (nonzero) digits is 75600, while the sum is 40.

The spelling of 66116570521 in words is "sixty-six billion, one hundred sixteen million, five hundred seventy thousand, five hundred twenty-one".