90099919991 has 4 divisors (see below), whose sum is σ = 90105226752. Its totient is φ = 90094613232.

The previous prime is 90099919937. The next prime is 90099919999. The reversal of 90099919991 is 19991999009.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 90099919991 - 2¹⁰ = 90099918967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90099919999) 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, 2627831 + ... + 2661896.

It is an arithmetic number, because the mean of its divisors is an integer number (22526306688).

Almost surely, 2^90099919991 is an apocalyptic number.

90099919991 is a deficient number, since it is larger than the sum of its proper divisors (5306761).

90099919991 is a wasteful number, since it uses less digits than its factorization.

90099919991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5306760.

The product of its (nonzero) digits is 4782969, while the sum is 65.

The spelling of 90099919991 in words is "ninety billion, ninety-nine million, nine hundred nineteen thousand, nine hundred ninety-one".