131556401 has 2 divisors, whose sum is σ = 131556402. Its totient is φ = 131556400.

The previous prime is 131556317. The next prime is 131556427. The reversal of 131556401 is 104655131.

It is an a-pointer prime, because the next prime (131556427) can be obtained adding 131556401 to its sum of digits (26).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77018176 + 54538225 = 8776^2 + 7385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131556401 is a prime.

It is not a weakly prime, because it can be changed into another prime (131556461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65778200 + 65778201.

It is an arithmetic number, because the mean of its divisors is an integer number (65778201).

Almost surely, 2^131556401 is an apocalyptic number.

It is an amenable number.

131556401 is a deficient number, since it is larger than the sum of its proper divisors (1).

131556401 is an equidigital number, since it uses as much as digits as its factorization.

131556401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 131556401 is about 11469.8038780094. The cubic root of 131556401 is about 508.5933312140.

The spelling of 131556401 in words is "one hundred thirty-one million, five hundred fifty-six thousand, four hundred one".