66690418 has 12 divisors (see below), whose sum is σ = 105578910. Its totient is φ = 31589856.

The previous prime is 66690413. The next prime is 66690427. The reversal of 66690418 is 81409666.

It can be written as a sum of positive squares in only one way, i.e., 54066609 + 12623809 = 7353^2 + 3553^2 .

It is a super-2 number, since 2×66690418² = 8895223706029448, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66690413) 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 5 ways as a sum of consecutive naturals, for example, 45463 + ... + 46906.

Almost surely, 2^66690418 is an apocalyptic number.

66690418 is a deficient number, since it is larger than the sum of its proper divisors (38888492).

66690418 is a wasteful number, since it uses less digits than its factorization.

66690418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92409 (or 92390 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 66690418 is about 8166.4201459391. The cubic root of 66690418 is about 405.5282807898.

The spelling of 66690418 in words is "sixty-six million, six hundred ninety thousand, four hundred eighteen".