66185661 has 8 divisors (see below), whose sum is σ = 88789600. Its totient is φ = 43852752.

The previous prime is 66185629. The next prime is 66185663. The reversal of 66185661 is 16658166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66185661 - 2⁵ = 66185629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66185663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67186 + ... + 68163.

It is an arithmetic number, because the mean of its divisors is an integer number (11098700).

Almost surely, 2^66185661 is an apocalyptic number.

It is an amenable number.

66185661 is a deficient number, since it is larger than the sum of its proper divisors (22603939).

66185661 is a wasteful number, since it uses less digits than its factorization.

66185661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135515.

The product of its digits is 51840, while the sum is 39.

The square root of 66185661 is about 8135.4570246545. The cubic root of 66185661 is about 404.5025870206.

The spelling of 66185661 in words is "sixty-six million, one hundred eighty-five thousand, six hundred sixty-one".