131356221 has 4 divisors (see below), whose sum is σ = 175141632. Its totient is φ = 87570812.

The previous prime is 131356217. The next prime is 131356249. The reversal of 131356221 is 122653131.

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: 122653131 = 3 ⋅40884377.

It is a cyclic number.

It is not a de Polignac number, because 131356221 - 2² = 131356217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 131356191 and 131356200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131316221) 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, 21892701 + ... + 21892706.

It is an arithmetic number, because the mean of its divisors is an integer number (43785408).

Almost surely, 2^131356221 is an apocalyptic number.

It is an amenable number.

131356221 is a deficient number, since it is larger than the sum of its proper divisors (43785411).

131356221 is an equidigital number, since it uses as much as digits as its factorization.

131356221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43785410.

The product of its digits is 1080, while the sum is 24.

The square root of 131356221 is about 11461.0741643181. The cubic root of 131356221 is about 508.3352368527.

The spelling of 131356221 in words is "one hundred thirty-one million, three hundred fifty-six thousand, two hundred twenty-one".