131121 has 12 divisors (see below), whose sum is σ = 200772. Its totient is φ = 82176.

The previous prime is 131113. The next prime is 131129. The reversal of 131121 is 121131.

It is an interprime number because it is at equal distance from previous prime (131113) and next prime (131129).

It can be written as a sum of positive squares in 2 ways, for example, as 112896 + 18225 = 336^2 + 135^2 .

It is not a de Polignac number, because 131121 - 2³ = 131113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (131129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 276 + ... + 581.

It is an arithmetic number, because the mean of its divisors is an integer number (16731).

2¹³¹¹²¹ is an apocalyptic number.

It is an amenable number.

131121 is a deficient number, since it is larger than the sum of its proper divisors (69651).

131121 is a wasteful number, since it uses less digits than its factorization.

131121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880 (or 877 counting only the distinct ones).

The product of its digits is 6, while the sum is 9.

The square root of 131121 is about 362.1063379727. The cubic root of 131121 is about 50.8031628427.

Adding to 131121 its reverse (121131), we get a palindrome (252252).

It can be divided in two parts, 131 and 121, that multiplied together give a palindrome (15851).

The spelling of 131121 in words is "one hundred thirty-one thousand, one hundred twenty-one".