90110021 has 4 divisors (see below), whose sum is σ = 94027872. Its totient is φ = 86192172.

The previous prime is 90110011. The next prime is 90110023. The reversal of 90110021 is 12001109.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 90110021 - 2²⁶ = 23001157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90109978 and 90110005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90110023) 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, 1958891 + ... + 1958936.

It is an arithmetic number, because the mean of its divisors is an integer number (23506968).

Almost surely, 2^90110021 is an apocalyptic number.

It is an amenable number.

90110021 is a deficient number, since it is larger than the sum of its proper divisors (3917851).

90110021 is a wasteful number, since it uses less digits than its factorization.

90110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3917850.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 90110021 is about 9492.6298252908. The cubic root of 90110021 is about 448.3230108994.

The spelling of 90110021 in words is "ninety million, one hundred ten thousand, twenty-one".