131213561 has 2 divisors, whose sum is σ = 131213562. Its totient is φ = 131213560.

The previous prime is 131213477. The next prime is 131213569. The reversal of 131213561 is 165312131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92525161 + 38688400 = 9619^2 + 6220^2 .

It is a cyclic number.

It is not a de Polignac number, because 131213561 - 2²⁶ = 64104697 is a prime.

It is not a weakly prime, because it can be changed into another prime (131213569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65606780 + 65606781.

It is an arithmetic number, because the mean of its divisors is an integer number (65606781).

Almost surely, 2^131213561 is an apocalyptic number.

It is an amenable number.

131213561 is a deficient number, since it is larger than the sum of its proper divisors (1).

131213561 is an equidigital number, since it uses as much as digits as its factorization.

131213561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 23.

The square root of 131213561 is about 11454.8487986529. The cubic root of 131213561 is about 508.1511436203.

Adding to 131213561 its reverse (165312131), we get a palindrome (296525692).

The spelling of 131213561 in words is "one hundred thirty-one million, two hundred thirteen thousand, five hundred sixty-one".