665491631 has 8 divisors (see below), whose sum is σ = 761266464. Its totient is φ = 569892960.

The previous prime is 665491627. The next prime is 665491649. The reversal of 665491631 is 136194566.

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

It is not a de Polignac number, because 665491631 - 2² = 665491627 is a prime.

It is a super-2 number, since 2×665491631² = 885758221862080322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665491331) 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, 35840 + ... + 51141.

It is an arithmetic number, because the mean of its divisors is an integer number (95158308).

Almost surely, 2^665491631 is an apocalyptic number.

665491631 is a deficient number, since it is larger than the sum of its proper divisors (95774833).

665491631 is a wasteful number, since it uses less digits than its factorization.

665491631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88081.

The product of its digits is 116640, while the sum is 41.

The square root of 665491631 is about 25797.1244715375. The cubic root of 665491631 is about 873.0669187987.

The spelling of 665491631 in words is "six hundred sixty-five million, four hundred ninety-one thousand, six hundred thirty-one".