66172761 has 16 divisors (see below), whose sum is σ = 100684800. Its totient is φ = 42922224.

The previous prime is 66172753. The next prime is 66172907. The reversal of 66172761 is 16727166.

It is not a de Polignac number, because 66172761 - 2³ = 66172753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66172741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32121 + ... + 34118.

It is an arithmetic number, because the mean of its divisors is an integer number (6292800).

Almost surely, 2^66172761 is an apocalyptic number.

It is an amenable number.

66172761 is a deficient number, since it is larger than the sum of its proper divisors (34512039).

66172761 is a wasteful number, since it uses less digits than its factorization.

66172761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66285 (or 66279 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 66172761 is about 8134.6641602466. The cubic root of 66172761 is about 404.4763052835.

The spelling of 66172761 in words is "sixty-six million, one hundred seventy-two thousand, seven hundred sixty-one".