131220857 has 2 divisors, whose sum is σ = 131220858. Its totient is φ = 131220856.

The previous prime is 131220847. The next prime is 131220863. The reversal of 131220857 is 758022131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122124601 + 9096256 = 11051^2 + 3016^2 .

It is a cyclic number.

It is not a de Polignac number, because 131220857 - 2²² = 127026553 is a prime.

It is not a weakly prime, because it can be changed into another prime (131220827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65610428 + 65610429.

It is an arithmetic number, because the mean of its divisors is an integer number (65610429).

Almost surely, 2^131220857 is an apocalyptic number.

It is an amenable number.

131220857 is a deficient number, since it is larger than the sum of its proper divisors (1).

131220857 is an equidigital number, since it uses as much as digits as its factorization.

131220857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 131220857 is about 11455.1672619827. The cubic root of 131220857 is about 508.1605618593.

Adding to 131220857 its reverse (758022131), we get a palindrome (889242988).

The spelling of 131220857 in words is "one hundred thirty-one million, two hundred twenty thousand, eight hundred fifty-seven".