165131563 has 4 divisors (see below), whose sum is σ = 165301560. Its totient is φ = 164961568.

The previous prime is 165131537. The next prime is 165131569. The reversal of 165131563 is 365131561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 365131561 = 5431 ⋅67231.

It is a cyclic number.

It is not a de Polignac number, because 165131563 - 2⁵ = 165131531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165131569) 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, 83533 + ... + 85486.

It is an arithmetic number, because the mean of its divisors is an integer number (41325390).

Almost surely, 2^165131563 is an apocalyptic number.

165131563 is a deficient number, since it is larger than the sum of its proper divisors (169997).

165131563 is an equidigital number, since it uses as much as digits as its factorization.

165131563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169996.

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

The square root of 165131563 is about 12850.3526410757. The cubic root of 165131563 is about 548.6263938090.

The spelling of 165131563 in words is "one hundred sixty-five million, one hundred thirty-one thousand, five hundred sixty-three".