165356531 has 4 divisors (see below), whose sum is σ = 166222464. Its totient is φ = 164490600.

The previous prime is 165356519. The next prime is 165356539. The reversal of 165356531 is 135653561.

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: 135653561 = 29 ⋅4677709.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165356531 is a prime.

It is a super-2 number, since 2×165356531² = 54685564688707922, 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 = 165356491 and 165356500.

It is not an unprimeable number, because it can be changed into a prime (165356539) 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 3 ways as a sum of consecutive naturals, for example, 432680 + ... + 433061.

It is an arithmetic number, because the mean of its divisors is an integer number (41555616).

Almost surely, 2^165356531 is an apocalyptic number.

165356531 is a deficient number, since it is larger than the sum of its proper divisors (865933).

165356531 is an equidigital number, since it uses as much as digits as its factorization.

165356531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865932.

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

The square root of 165356531 is about 12859.1030402591. The cubic root of 165356531 is about 548.8754222682.

The spelling of 165356531 in words is "one hundred sixty-five million, three hundred fifty-six thousand, five hundred thirty-one".