131220031 has 4 divisors (see below), whose sum is σ = 132164200. Its totient is φ = 130275864.

The previous prime is 131220029. The next prime is 131220077. The reversal of 131220031 is 130022131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130022131 = 7993 ⋅16267.

It is a cyclic number.

It is not a de Polignac number, because 131220031 - 2¹ = 131220029 is a prime.

It is a super-2 number, since 2×131220031² = 34437393071281922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131219993 and 131220020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131220731) 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, 471876 + ... + 472153.

It is an arithmetic number, because the mean of its divisors is an integer number (33041050).

Almost surely, 2^131220031 is an apocalyptic number.

131220031 is a deficient number, since it is larger than the sum of its proper divisors (944169).

131220031 is an equidigital number, since it uses as much as digits as its factorization.

131220031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944168.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 131220031 is about 11455.1312083276. The cubic root of 131220031 is about 508.1594956124.

Adding to 131220031 its reverse (130022131), we get a palindrome (261242162).

The spelling of 131220031 in words is "one hundred thirty-one million, two hundred twenty thousand, thirty-one".