161131541 has 4 divisors (see below), whose sum is σ = 161681772. Its totient is φ = 160581312.

The previous prime is 161131519. The next prime is 161131543. The reversal of 161131541 is 145131161.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 146918641 + 14212900 = 12121^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 161131541 - 2²² = 156937237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161131543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 274676 + ... + 275261.

It is an arithmetic number, because the mean of its divisors is an integer number (40420443).

Almost surely, 2^161131541 is an apocalyptic number.

It is an amenable number.

161131541 is a deficient number, since it is larger than the sum of its proper divisors (550231).

161131541 is an equidigital number, since it uses as much as digits as its factorization.

161131541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550230.

The product of its digits is 360, while the sum is 23.

The square root of 161131541 is about 12693.7599236790. The cubic root of 161131541 is about 544.1602993667.

The spelling of 161131541 in words is "one hundred sixty-one million, one hundred thirty-one thousand, five hundred forty-one".