9090991 has 8 divisors (see below), whose sum is σ = 11189024. Its totient is φ = 7192800.

The previous prime is 9090989. The next prime is 9091009. The reversal of 9090991 is 1990909.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9090991 - 2¹ = 9090989 is a prime.

It is a super-2 number, since 2×9090991² = 165292234724162, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 9090991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9090901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49860 + ... + 50041.

It is an arithmetic number, because the mean of its divisors is an integer number (1398628).

Almost surely, 2^9090991 is an apocalyptic number.

9090991 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

9090991 is a deficient number, since it is larger than the sum of its proper divisors (2098033).

9090991 is a wasteful number, since it uses less digits than its factorization.

9090991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99921.

The product of its (nonzero) digits is 6561, while the sum is 37.

The square root of 9090991 is about 3015.1270288331. The cubic root of 9090991 is about 208.7070290553.

The spelling of 9090991 in words is "nine million, ninety thousand, nine hundred ninety-one".