131361781 has 2 divisors, whose sum is σ = 131361782. Its totient is φ = 131361780.

The previous prime is 131361773. The next prime is 131361829. The reversal of 131361781 is 187163131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 124679556 + 6682225 = 11166^2 + 2585^2 .

It is a cyclic number.

It is not a de Polignac number, because 131361781 - 2³ = 131361773 is a prime.

It is a super-2 number, since 2×131361781² = 34511835014983922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131361701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65680890 + 65680891.

It is an arithmetic number, because the mean of its divisors is an integer number (65680891).

Almost surely, 2^131361781 is an apocalyptic number.

It is an amenable number.

131361781 is a deficient number, since it is larger than the sum of its proper divisors (1).

131361781 is an equidigital number, since it uses as much as digits as its factorization.

131361781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 31.

The square root of 131361781 is about 11461.3167219129. The cubic root of 131361781 is about 508.3424089633.

The spelling of 131361781 in words is "one hundred thirty-one million, three hundred sixty-one thousand, seven hundred eighty-one".