131242021 has 4 divisors (see below), whose sum is σ = 131929344. Its totient is φ = 130554700.

The previous prime is 131241959. The next prime is 131242037. The reversal of 131242021 is 120242131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120242131 = 10861 ⋅11071.

It is a cyclic number.

It is not a de Polignac number, because 131242021 - 2¹⁹ = 130717733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131241986 and 131242004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131242061) 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, 343375 + ... + 343756.

It is an arithmetic number, because the mean of its divisors is an integer number (32982336).

Almost surely, 2^131242021 is an apocalyptic number.

It is an amenable number.

131242021 is a deficient number, since it is larger than the sum of its proper divisors (687323).

131242021 is an equidigital number, since it uses as much as digits as its factorization.

131242021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687322.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 131242021 is about 11456.0909999877. The cubic root of 131242021 is about 508.1878800063.

Adding to 131242021 its reverse (120242131), we get a palindrome (251484152).

The spelling of 131242021 in words is "one hundred thirty-one million, two hundred forty-two thousand, twenty-one".