66478131 has 16 divisors (see below), whose sum is σ = 103670400. Its totient is φ = 41985864.

The previous prime is 66478127. The next prime is 66478141. The reversal of 66478131 is 13187466.

66478131 is a `hidden beast` number, since 6 + 647 + 8 + 1 + 3 + 1 = 666.

It is not a de Polignac number, because 66478131 - 2² = 66478127 is a prime.

It is a super-2 number, since 2×66478131² = 8838683802506322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66478141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64281 + ... + 65306.

It is an arithmetic number, because the mean of its divisors is an integer number (6479400).

Almost surely, 2^66478131 is an apocalyptic number.

66478131 is a deficient number, since it is larger than the sum of its proper divisors (37192269).

66478131 is a wasteful number, since it uses less digits than its factorization.

66478131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129615 (or 129609 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 66478131 is about 8153.4122304714. The cubic root of 66478131 is about 405.0975348082.

The spelling of 66478131 in words is "sixty-six million, four hundred seventy-eight thousand, one hundred thirty-one".