165215131 has 4 divisors (see below), whose sum is σ = 165256000. Its totient is φ = 165174264.

The previous prime is 165215119. The next prime is 165215161. The reversal of 165215131 is 131512561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 131512561 = 17 ⋅7736033.

It is a cyclic number.

It is not a de Polignac number, because 165215131 - 2¹⁹ = 164690843 is a prime.

It is a super-2 number, since 2×165215131² = 54592079022694322, 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 = 165215096 and 165215105.

It is not an unprimeable number, because it can be changed into a prime (165215161) 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, 13611 + ... + 22708.

It is an arithmetic number, because the mean of its divisors is an integer number (41314000).

Almost surely, 2^165215131 is an apocalyptic number.

165215131 is a deficient number, since it is larger than the sum of its proper divisors (40869).

165215131 is an equidigital number, since it uses as much as digits as its factorization.

165215131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40868.

The product of its digits is 900, while the sum is 25.

The square root of 165215131 is about 12853.6038137170. The cubic root of 165215131 is about 548.7189258439.

Adding to 165215131 its reverse (131512561), we get a palindrome (296727692).

It can be divided in two parts, 165 and 215131, that added together give a square (215296 = 464²).

The spelling of 165215131 in words is "one hundred sixty-five million, two hundred fifteen thousand, one hundred thirty-one".