90910091 has 4 divisors (see below), whose sum is σ = 92451000. Its totient is φ = 89369184.

The previous prime is 90910081. The next prime is 90910093. The reversal of 90910091 is 19001909.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19001909 = 709 ⋅26801.

It is a cyclic number.

It is not a de Polignac number, because 90910091 - 2¹⁴ = 90893707 is a prime.

It is a super-3 number, since 3×90910091³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90910093) 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, 770366 + ... + 770483.

It is an arithmetic number, because the mean of its divisors is an integer number (23112750).

Almost surely, 2^90910091 is an apocalyptic number.

90910091 is a deficient number, since it is larger than the sum of its proper divisors (1540909).

90910091 is a wasteful number, since it uses less digits than its factorization.

90910091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540908.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 90910091 is about 9534.6783375214. The cubic root of 90910091 is about 449.6459618623.

It can be divided in two parts, 909 and 10091, that multiplied together give a palindrome (9172719).

The spelling of 90910091 in words is "ninety million, nine hundred ten thousand, ninety-one".