66561136 has 20 divisors (see below), whose sum is σ = 129258592. Its totient is φ = 33204096.

The previous prime is 66561133. The next prime is 66561197. The reversal of 66561136 is 63116566.

It is a super-2 number, since 2×66561136² = 8860769651220992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66561133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2761 + ... + 11863.

Almost surely, 2^66561136 is an apocalyptic number.

It is an amenable number.

66561136 is a deficient number, since it is larger than the sum of its proper divisors (62697456).

66561136 is a wasteful number, since it uses less digits than its factorization.

66561136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9568 (or 9562 counting only the distinct ones).

The product of its digits is 19440, while the sum is 34.

The square root of 66561136 is about 8158.5008426794. The cubic root of 66561136 is about 405.2660671021.

The spelling of 66561136 in words is "sixty-six million, five hundred sixty-one thousand, one hundred thirty-six".