665612831 has 4 divisors (see below), whose sum is σ = 716813832. Its totient is φ = 614411832.

The previous prime is 665612821. The next prime is 665612833. The reversal of 665612831 is 138216566.

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 665612831 - 2⁶ = 665612767 is a prime.

It is a super-2 number, since 2×665612831² = 886080881583669122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665612833) 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 3 ways as a sum of consecutive naturals, for example, 25600481 + ... + 25600506.

It is an arithmetic number, because the mean of its divisors is an integer number (179203458).

Almost surely, 2^665612831 is an apocalyptic number.

665612831 is a deficient number, since it is larger than the sum of its proper divisors (51201001).

665612831 is a wasteful number, since it uses less digits than its factorization.

665612831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51201000.

The product of its digits is 51840, while the sum is 38.

The square root of 665612831 is about 25799.4734636194. The cubic root of 665612831 is about 873.1199168544.

The spelling of 665612831 in words is "six hundred sixty-five million, six hundred twelve thousand, eight hundred thirty-one".