131220431 has 4 divisors (see below), whose sum is σ = 131719632. Its totient is φ = 130721232.

The previous prime is 131220409. The next prime is 131220449. The reversal of 131220431 is 134022131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 134022131 = 1493 ⋅89767.

It is a cyclic number.

It is not a de Polignac number, because 131220431 - 2⁶ = 131220367 is a prime.

It is a super-2 number, since 2×131220431² = 34437603023651522, which contains 22 as substring.

It is a Duffinian number.

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, 249206 + ... + 249731.

It is an arithmetic number, because the mean of its divisors is an integer number (32929908).

Almost surely, 2^131220431 is an apocalyptic number.

131220431 is a deficient number, since it is larger than the sum of its proper divisors (499201).

131220431 is an equidigital number, since it uses as much as digits as its factorization.

131220431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499200.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 131220431 is about 11455.1486677389. The cubic root of 131220431 is about 508.1600119553.

Adding to 131220431 its reverse (134022131), we get a palindrome (265242562).

The spelling of 131220431 in words is "one hundred thirty-one million, two hundred twenty thousand, four hundred thirty-one".