90001921 has 4 divisors (see below), whose sum is σ = 93915072. Its totient is φ = 86088772.

The previous prime is 90001909. The next prime is 90001931. The reversal of 90001921 is 12910009.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12910009 = 7 ⋅1844287.

It is a cyclic number.

It is not a de Polignac number, because 90001921 - 2¹⁷ = 89870849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 90001892 and 90001901.

It is not an unprimeable number, because it can be changed into a prime (90001931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1956541 + ... + 1956586.

It is an arithmetic number, because the mean of its divisors is an integer number (23478768).

Almost surely, 2^90001921 is an apocalyptic number.

It is an amenable number.

90001921 is a deficient number, since it is larger than the sum of its proper divisors (3913151).

90001921 is a wasteful number, since it uses less digits than its factorization.

90001921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3913150.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 90001921 is about 9486.9342255546. The cubic root of 90001921 is about 448.1436630695.

The spelling of 90001921 in words is "ninety million, one thousand, nine hundred twenty-one".