131091021 has 8 divisors (see below), whose sum is σ = 194208960. Its totient is φ = 87393996.

The previous prime is 131091019. The next prime is 131091043. The reversal of 131091021 is 120190131.

It is not a de Polignac number, because 131091021 - 2¹ = 131091019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 131090985 and 131091003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131091001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2427585 + ... + 2427638.

It is an arithmetic number, because the mean of its divisors is an integer number (24276120).

Almost surely, 2^131091021 is an apocalyptic number.

It is an amenable number.

131091021 is a deficient number, since it is larger than the sum of its proper divisors (63117939).

131091021 is an equidigital number, since it uses as much as digits as its factorization.

131091021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4855232 (or 4855226 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 18.

The square root of 131091021 is about 11449.4987226516. The cubic root of 131091021 is about 507.9929073451.

The spelling of 131091021 in words is "one hundred thirty-one million, ninety-one thousand, twenty-one".