131131421 has 4 divisors (see below), whose sum is σ = 138845052. Its totient is φ = 123417792.

The previous prime is 131131409. The next prime is 131131439. The reversal of 131131421 is 124131131.

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 72914521 + 58216900 = 8539^2 + 7630^2 .

It is a cyclic number.

It is not a de Polignac number, because 131131421 - 2²⁶ = 64022557 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 7713613 = 131131421 / (1 + 3 + 1 + 1 + 3 + 1 + 4 + 2 + 1).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 131131421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131131471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3856790 + ... + 3856823.

It is an arithmetic number, because the mean of its divisors is an integer number (34711263).

Almost surely, 2^131131421 is an apocalyptic number.

It is an amenable number.

131131421 is a deficient number, since it is larger than the sum of its proper divisors (7713631).

131131421 is an equidigital number, since it uses as much as digits as its factorization.

131131421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7713630.

The product of its digits is 72, while the sum is 17.

The square root of 131131421 is about 11451.2628561220. The cubic root of 131131421 is about 508.0450868801.

Adding to 131131421 its reverse (124131131), we get a palindrome (255262552).

The spelling of 131131421 in words is "one hundred thirty-one million, one hundred thirty-one thousand, four hundred twenty-one".