665135131 has 4 divisors (see below), whose sum is σ = 665253352. Its totient is φ = 665016912.

The previous prime is 665135129. The next prime is 665135167. The reversal of 665135131 is 131531566.

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 665135131 - 2¹ = 665135129 is a prime.

It is a super-2 number, since 2×665135131² = 884809484980774322, 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 = 665135093 and 665135102.

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 3 ways as a sum of consecutive naturals, for example, 50226 + ... + 62071.

It is an arithmetic number, because the mean of its divisors is an integer number (166313338).

Almost surely, 2^665135131 is an apocalyptic number.

665135131 is a deficient number, since it is larger than the sum of its proper divisors (118221).

665135131 is a wasteful number, since it uses less digits than its factorization.

665135131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118220.

The product of its digits is 8100, while the sum is 31.

The square root of 665135131 is about 25790.2138610753. The cubic root of 665135131 is about 872.9109919939.

Adding to 665135131 its reverse (131531566), we get a palindrome (796666697).

The spelling of 665135131 in words is "six hundred sixty-five million, one hundred thirty-five thousand, one hundred thirty-one".