131820981 has 12 divisors (see below), whose sum is σ = 183737568. Its totient is φ = 84058744.

The previous prime is 131820971. The next prime is 131821007. The reversal of 131820981 is 189028131.

It is not a de Polignac number, because 131820981 - 2¹¹ = 131818933 is a prime.

It is a super-2 number, since 2×131820981² = 34753542063604722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131820961) 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 in 11 ways as a sum of consecutive naturals, for example, 39945 + ... + 43118.

It is an arithmetic number, because the mean of its divisors is an integer number (15311464).

Almost surely, 2^131820981 is an apocalyptic number.

It is an amenable number.

131820981 is a deficient number, since it is larger than the sum of its proper divisors (51916587).

131820981 is an equidigital number, since it uses as much as digits as its factorization.

131820981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83112 (or 83089 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 33.

The square root of 131820981 is about 11481.3318478302. The cubic root of 131820981 is about 508.9340558357.

The spelling of 131820981 in words is "one hundred thirty-one million, eight hundred twenty thousand, nine hundred eighty-one".