131220091 has 4 divisors (see below), whose sum is σ = 131463184. Its totient is φ = 130977000.

The previous prime is 131220079. The next prime is 131220101. The reversal of 131220091 is 190022131.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 131220091 - 2⁹ = 131219579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131220191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120735 + ... + 121816.

It is an arithmetic number, because the mean of its divisors is an integer number (32865796).

Almost surely, 2^131220091 is an apocalyptic number.

131220091 is a deficient number, since it is larger than the sum of its proper divisors (243093).

131220091 is an equidigital number, since it uses as much as digits as its factorization.

131220091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243092.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 131220091 is about 11455.1338272410. The cubic root of 131220091 is about 508.1595730639.

The spelling of 131220091 in words is "one hundred thirty-one million, two hundred twenty thousand, ninety-one".