66185649 has 6 divisors (see below), whose sum is σ = 95601506. Its totient is φ = 44123760.

The previous prime is 66185629. The next prime is 66185663. The reversal of 66185649 is 94658166.

It can be written as a sum of positive squares in only one way, i.e., 64112049 + 2073600 = 8007^2 + 1440^2 .

It is not a de Polignac number, because 66185649 - 2⁵ = 66185617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66185629) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3676972 + ... + 3676989.

Almost surely, 2^66185649 is an apocalyptic number.

It is an amenable number.

66185649 is a deficient number, since it is larger than the sum of its proper divisors (29415857).

66185649 is a wasteful number, since it uses less digits than its factorization.

66185649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7353967 (or 7353964 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 66185649 is about 8135.4562871421. The cubic root of 66185649 is about 404.5025625741.

The spelling of 66185649 in words is "sixty-six million, one hundred eighty-five thousand, six hundred forty-nine".