666671731 has 4 divisors (see below), whose sum is σ = 727278264. Its totient is φ = 606065200.

The previous prime is 666671713. The next prime is 666671737. The reversal of 666671731 is 137176666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666671731 - 2¹¹ = 666669683 is a prime.

It is a super-2 number, since 2×666671731² = 888902393829072722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666671737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30303250 + ... + 30303271.

It is an arithmetic number, because the mean of its divisors is an integer number (181819566).

Almost surely, 2^666671731 is an apocalyptic number.

666671731 is a deficient number, since it is larger than the sum of its proper divisors (60606533).

666671731 is a wasteful number, since it uses less digits than its factorization.

666671731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60606532.

The product of its digits is 190512, while the sum is 43.

The square root of 666671731 is about 25819.9870449232. The cubic root of 666671731 is about 873.5826767820.

The spelling of 666671731 in words is "six hundred sixty-six million, six hundred seventy-one thousand, seven hundred thirty-one".