91982181 has 4 divisors (see below), whose sum is σ = 122642912. Its totient is φ = 61321452.

The previous prime is 91982159. The next prime is 91982227. The reversal of 91982181 is 18128919.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 91982181 - 2²⁵ = 58427749 is a prime.

It is a super-2 number, since 2×91982181² = 16921443243033522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91982141) 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, 15330361 + ... + 15330366.

It is an arithmetic number, because the mean of its divisors is an integer number (30660728).

Almost surely, 2^91982181 is an apocalyptic number.

It is an amenable number.

91982181 is a deficient number, since it is larger than the sum of its proper divisors (30660731).

91982181 is a wasteful number, since it uses less digits than its factorization.

91982181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30660730.

The product of its digits is 10368, while the sum is 39.

The square root of 91982181 is about 9590.7341220576. The cubic root of 91982181 is about 451.4065962542.

The spelling of 91982181 in words is "ninety-one million, nine hundred eighty-two thousand, one hundred eighty-one".