90919091 has 8 divisors (see below), whose sum is σ = 92847504. Its totient is φ = 89009280.

The previous prime is 90919079. The next prime is 90919093. The reversal of 90919091 is 19091909.

It is a happy number.

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 90919091 - 2¹⁸ = 90656947 is a prime.

It is a super-2 number, since 2×90919091² = 16532562216532562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90919093) 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, 5456 + ... + 14546.

It is an arithmetic number, because the mean of its divisors is an integer number (11605938).

Almost surely, 2^90919091 is an apocalyptic number.

90919091 is a deficient number, since it is larger than the sum of its proper divisors (1928413).

90919091 is a wasteful number, since it uses less digits than its factorization.

90919091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9301.

The product of its (nonzero) digits is 6561, while the sum is 38.

The square root of 90919091 is about 9535.1502872267. The cubic root of 90919091 is about 449.6607995261.

The spelling of 90919091 in words is "ninety million, nine hundred nineteen thousand, ninety-one".