66478731 has 24 divisors (see below), whose sum is σ = 99718080. Its totient is φ = 39343920.

The previous prime is 66478723. The next prime is 66478757. The reversal of 66478731 is 13787466.

It is not a de Polignac number, because 66478731 - 2³ = 66478723 is a prime.

It is a super-2 number, since 2×66478731² = 8838843350740722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66478771) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13480 + ... + 17738.

It is an arithmetic number, because the mean of its divisors is an integer number (4154920).

Almost surely, 2^66478731 is an apocalyptic number.

66478731 is a deficient number, since it is larger than the sum of its proper divisors (33239349).

66478731 is a wasteful number, since it uses less digits than its factorization.

66478731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4327 (or 4316 counting only the distinct ones).

The product of its digits is 169344, while the sum is 42.

The square root of 66478731 is about 8153.4490247993. The cubic root of 66478731 is about 405.0987535437.

The spelling of 66478731 in words is "sixty-six million, four hundred seventy-eight thousand, seven hundred thirty-one".