665135531 has 8 divisors (see below), whose sum is σ = 678166560. Its totient is φ = 652122432.

The previous prime is 665135509. The next prime is 665135543. The reversal of 665135531 is 135531566.

It is a happy number.

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 665135531 - 2⁶ = 665135467 is a prime.

It is a super-2 number, since 2×665135531² = 884810549197303922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665135491 and 665135500.

It is not an unprimeable number, because it can be changed into a prime (665135431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89330 + ... + 96488.

It is an arithmetic number, because the mean of its divisors is an integer number (84770820).

Almost surely, 2^665135531 is an apocalyptic number.

665135531 is a deficient number, since it is larger than the sum of its proper divisors (13031029).

665135531 is a wasteful number, since it uses less digits than its factorization.

665135531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8965.

The product of its digits is 40500, while the sum is 35.

The square root of 665135531 is about 25790.2216159536. The cubic root of 665135531 is about 872.9111669780.

The spelling of 665135531 in words is "six hundred sixty-five million, one hundred thirty-five thousand, five hundred thirty-one".