9091981 has 4 divisors (see below), whose sum is σ = 9146592. Its totient is φ = 9037372.

The previous prime is 9091961. The next prime is 9091997. The reversal of 9091981 is 1891909.

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 9091981 - 2¹⁷ = 8960909 is a prime.

It is a super-2 number, since 2×9091981² = 165328237008722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9091981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9091921) 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 3 ways as a sum of consecutive naturals, for example, 27055 + ... + 27388.

It is an arithmetic number, because the mean of its divisors is an integer number (2286648).

Almost surely, 2^9091981 is an apocalyptic number.

It is an amenable number.

9091981 is a deficient number, since it is larger than the sum of its proper divisors (54611).

9091981 is a wasteful number, since it uses less digits than its factorization.

9091981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54610.

The product of its (nonzero) digits is 5832, while the sum is 37.

The square root of 9091981 is about 3015.2911965513. The cubic root of 9091981 is about 208.7146047772.

The spelling of 9091981 in words is "nine million, ninety-one thousand, nine hundred eighty-one".