90100091 has 4 divisors (see below), whose sum is σ = 90164832. Its totient is φ = 90035352.

The previous prime is 90100079. The next prime is 90100103. The reversal of 90100091 is 19000109.

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

It is an interprime number because it is at equal distance from previous prime (90100079) and next prime (90100103).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90100091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90100891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30236 + ... + 33081.

It is an arithmetic number, because the mean of its divisors is an integer number (22541208).

Almost surely, 2^90100091 is an apocalyptic number.

90100091 is a deficient number, since it is larger than the sum of its proper divisors (64741).

90100091 is a wasteful number, since it uses less digits than its factorization.

90100091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64740.

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 90100091 is about 9492.1067735250. The cubic root of 90100091 is about 448.3065421020.

The spelling of 90100091 in words is "ninety million, one hundred thousand, ninety-one".