66551165 has 4 divisors (see below), whose sum is σ = 79861404. Its totient is φ = 53240928.

The previous prime is 66551137. The next prime is 66551207. The reversal of 66551165 is 56115566.

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

It can be written as a sum of positive squares in 2 ways, for example, as 37185604 + 29365561 = 6098^2 + 5419^2 .

It is a cyclic number.

It is not a de Polignac number, because 66551165 - 2⁸ = 66550909 is a prime.

It is a Duffinian number.

It is a Curzon number.

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, 6655112 + ... + 6655121.

It is an arithmetic number, because the mean of its divisors is an integer number (19965351).

Almost surely, 2^66551165 is an apocalyptic number.

It is an amenable number.

66551165 is a deficient number, since it is larger than the sum of its proper divisors (13310239).

66551165 is a wasteful number, since it uses less digits than its factorization.

66551165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13310238.

The product of its digits is 27000, while the sum is 35.

The square root of 66551165 is about 8157.8897393873. The cubic root of 66551165 is about 405.2458295180.

The spelling of 66551165 in words is "sixty-six million, five hundred fifty-one thousand, one hundred sixty-five".