665623731 has 8 divisors (see below), whose sum is σ = 892145664. Its totient is φ = 441425480.

The previous prime is 665623711. The next prime is 665623753. The reversal of 665623731 is 137326566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665623731 - 2⁶ = 665623667 is a prime.

It is a super-2 number, since 2×665623731² = 886109902540720722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 665623731.

It is not an unprimeable number, because it can be changed into a prime (665623711) 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 7 ways as a sum of consecutive naturals, for example, 580251 + ... + 581396.

It is an arithmetic number, because the mean of its divisors is an integer number (111518208).

Almost surely, 2^665623731 is an apocalyptic number.

665623731 is a deficient number, since it is larger than the sum of its proper divisors (226521933).

665623731 is a wasteful number, since it uses less digits than its factorization.

665623731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161841.

The product of its digits is 136080, while the sum is 39.

The square root of 665623731 is about 25799.6847073758. The cubic root of 665623731 is about 873.1246828658.

The spelling of 665623731 in words is "six hundred sixty-five million, six hundred twenty-three thousand, seven hundred thirty-one".