131785861 has 2 divisors, whose sum is σ = 131785862. Its totient is φ = 131785860.

The previous prime is 131785847. The next prime is 131785877. The reversal of 131785861 is 168587131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122213025 + 9572836 = 11055^2 + 3094^2 .

It is a cyclic number.

It is not a de Polignac number, because 131785861 - 2⁷ = 131785733 is a prime.

It is a super-2 number, since 2×131785861² = 34735026319022642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131785811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65892930 + 65892931.

It is an arithmetic number, because the mean of its divisors is an integer number (65892931).

Almost surely, 2^131785861 is an apocalyptic number.

It is an amenable number.

131785861 is a deficient number, since it is larger than the sum of its proper divisors (1).

131785861 is an equidigital number, since it uses as much as digits as its factorization.

131785861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 40.

The square root of 131785861 is about 11479.8023066602. The cubic root of 131785861 is about 508.8888547571. Note that the first 4 decimals are identical.

It can be divided in two parts, 1317 and 85861, that added together give a palindrome (87178).

The spelling of 131785861 in words is "one hundred thirty-one million, seven hundred eighty-five thousand, eight hundred sixty-one".