90814921 has 4 divisors (see below), whose sum is σ = 93946500. Its totient is φ = 87683344.

The previous prime is 90814907. The next prime is 90814937. The reversal of 90814921 is 12941809.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12941809 = 71 ⋅182279.

It can be written as a sum of positive squares in 2 ways, for example, as 30969225 + 59845696 = 5565^2 + 7736^2 .

It is a cyclic number.

It is not a de Polignac number, because 90814921 - 2¹⁷ = 90683849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90814991) 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, 1565746 + ... + 1565803.

It is an arithmetic number, because the mean of its divisors is an integer number (23486625).

Almost surely, 2^90814921 is an apocalyptic number.

It is an amenable number.

90814921 is a deficient number, since it is larger than the sum of its proper divisors (3131579).

90814921 is a wasteful number, since it uses less digits than its factorization.

90814921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3131578.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 90814921 is about 9529.6863012378. The cubic root of 90814921 is about 449.4890018480.

The spelling of 90814921 in words is "ninety million, eight hundred fourteen thousand, nine hundred twenty-one".