66561116 has 12 divisors (see below), whose sum is σ = 116553360. Its totient is φ = 33260160.

The previous prime is 66561101. The next prime is 66561127. The reversal of 66561116 is 61116566.

It is a super-4 number, since 4×66561116⁴ (a number of 32 digits) contains 4444 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4076 + ... + 12236.

It is an arithmetic number, because the mean of its divisors is an integer number (9712780).

Almost surely, 2^66561116 is an apocalyptic number.

It is an amenable number.

66561116 is a deficient number, since it is larger than the sum of its proper divisors (49992244).

66561116 is a wasteful number, since it uses less digits than its factorization.

66561116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10204 (or 10202 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 66561116 is about 8158.4996169639. The cubic root of 66561116 is about 405.2660265112.

The spelling of 66561116 in words is "sixty-six million, five hundred sixty-one thousand, one hundred sixteen".