66713731 has 32 divisors (see below), whose sum is σ = 84925440. Its totient is φ = 51093504.

The previous prime is 66713723. The next prime is 66713741. The reversal of 66713731 is 13731766.

It is a happy number.

It is not a de Polignac number, because 66713731 - 2³ = 66713723 is a prime.

It is a super-2 number, since 2×66713731² = 8901443807880722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66713741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 345571 + ... + 345763.

It is an arithmetic number, because the mean of its divisors is an integer number (2653920).

Almost surely, 2^66713731 is an apocalyptic number.

66713731 is a deficient number, since it is larger than the sum of its proper divisors (18211709).

66713731 is a wasteful number, since it uses less digits than its factorization.

66713731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355.

The product of its digits is 15876, while the sum is 34.

The square root of 66713731 is about 8167.8473908368. The cubic root of 66713731 is about 405.5755288538.

The spelling of 66713731 in words is "sixty-six million, seven hundred thirteen thousand, seven hundred thirty-one".