131421281 has 2 divisors, whose sum is σ = 131421282. Its totient is φ = 131421280.

The previous prime is 131421239. The next prime is 131421289. The reversal of 131421281 is 182124131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 99600400 + 31820881 = 9980^2 + 5641^2 .

It is a cyclic number.

It is not a de Polignac number, because 131421281 - 2⁶ = 131421217 is a prime.

It is a super-2 number, since 2×131421281² = 34543106199361922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (131421289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65710640 + 65710641.

It is an arithmetic number, because the mean of its divisors is an integer number (65710641).

Almost surely, 2^131421281 is an apocalyptic number.

It is an amenable number.

131421281 is a deficient number, since it is larger than the sum of its proper divisors (1).

131421281 is an equidigital number, since it uses as much as digits as its factorization.

131421281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384, while the sum is 23.

The square root of 131421281 is about 11463.9121158529. The cubic root of 131421281 is about 508.4191481985.

The spelling of 131421281 in words is "one hundred thirty-one million, four hundred twenty-one thousand, two hundred eighty-one".