131661553 has 2 divisors, whose sum is σ = 131661554. Its totient is φ = 131661552.

The previous prime is 131661529. The next prime is 131661623. The reversal of 131661553 is 355166131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115605504 + 16056049 = 10752^2 + 4007^2 .

It is an emirp because it is prime and its reverse (355166131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131661553 - 2¹⁷ = 131530481 is a prime.

It is not a weakly prime, because it can be changed into another prime (131661353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65830776 + 65830777.

It is an arithmetic number, because the mean of its divisors is an integer number (65830777).

Almost surely, 2^131661553 is an apocalyptic number.

It is an amenable number.

131661553 is a deficient number, since it is larger than the sum of its proper divisors (1).

131661553 is an equidigital number, since it uses as much as digits as its factorization.

131661553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8100, while the sum is 31.

The square root of 131661553 is about 11474.3868245759. The cubic root of 131661553 is about 508.7288000149.

The spelling of 131661553 in words is "one hundred thirty-one million, six hundred sixty-one thousand, five hundred fifty-three".