165631231 has 16 divisors (see below), whose sum is σ = 172368000. Its totient is φ = 159078688.

The previous prime is 165631229. The next prime is 165631253. The reversal of 165631231 is 132136561.

It is a cyclic number.

It is not a de Polignac number, because 165631231 - 2¹ = 165631229 is a prime.

It is a super-2 number, since 2×165631231² = 54867409365150722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165631231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165631261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 729540 + ... + 729766.

It is an arithmetic number, because the mean of its divisors is an integer number (10773000).

Almost surely, 2^165631231 is an apocalyptic number.

165631231 is a deficient number, since it is larger than the sum of its proper divisors (6736769).

165631231 is a wasteful number, since it uses less digits than its factorization.

165631231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518.

The product of its digits is 3240, while the sum is 28.

The square root of 165631231 is about 12869.7797572453. The cubic root of 165631231 is about 549.1791954986.

Adding to 165631231 its reverse (132136561), we get a palindrome (297767792).

The spelling of 165631231 in words is "one hundred sixty-five million, six hundred thirty-one thousand, two hundred thirty-one".