90009021 has 8 divisors (see below), whose sum is σ = 120096544. Its totient is φ = 59963760.

The previous prime is 90009001. The next prime is 90009037. The reversal of 90009021 is 12090009.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 90009021 - 2⁹ = 90008509 is a prime.

It is a super-2 number, since 2×90009021² = 16203247722756882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90009001) 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, 5206 + ... + 14391.

It is an arithmetic number, because the mean of its divisors is an integer number (15012068).

Almost surely, 2^90009021 is an apocalyptic number.

It is an amenable number.

90009021 is a deficient number, since it is larger than the sum of its proper divisors (30087523).

90009021 is a wasteful number, since it uses less digits than its factorization.

90009021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21131.

The product of its (nonzero) digits is 162, while the sum is 21.

The square root of 90009021 is about 9487.3084170380. The cubic root of 90009021 is about 448.1554470267.

The spelling of 90009021 in words is "ninety million, nine thousand, twenty-one".