131121531 has 16 divisors (see below), whose sum is σ = 195788800. Its totient is φ = 86723784.

The previous prime is 131121521. The next prime is 131121539. The reversal of 131121531 is 135121131.

131121531 is a `hidden beast` number, since 13 + 1 + 121 + 531 = 666.

It is not a de Polignac number, because 131121531 - 2¹⁴ = 131105147 is a prime.

It is a super-2 number, since 2×131121531² = 34385711783567922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131121539) 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, 15691 + ... + 22548.

It is an arithmetic number, because the mean of its divisors is an integer number (12236800).

Almost surely, 2^131121531 is an apocalyptic number.

131121531 is a deficient number, since it is larger than the sum of its proper divisors (64667269).

131121531 is a wasteful number, since it uses less digits than its factorization.

131121531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38375 (or 38369 counting only the distinct ones).

The product of its digits is 90, while the sum is 18.

The square root of 131121531 is about 11450.8310178781. The cubic root of 131121531 is about 508.0323142174.

Adding to 131121531 its reverse (135121131), we get a palindrome (266242662).

The spelling of 131121531 in words is "one hundred thirty-one million, one hundred twenty-one thousand, five hundred thirty-one".