90819021 has 8 divisors (see below), whose sum is σ = 121261504. Its totient is φ = 60461280.

The previous prime is 90819007. The next prime is 90819041. The reversal of 90819021 is 12091809.

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

It is not a de Polignac number, because 90819021 - 2⁹ = 90818509 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 90819021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90819041) 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, 18640 + ... + 23001.

It is an arithmetic number, because the mean of its divisors is an integer number (15157688).

Almost surely, 2^90819021 is an apocalyptic number.

It is an amenable number.

90819021 is a deficient number, since it is larger than the sum of its proper divisors (30442483).

90819021 is a wasteful number, since it uses less digits than its factorization.

90819021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42371.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 90819021 is about 9529.9014160693. The cubic root of 90819021 is about 449.4957660711.

The spelling of 90819021 in words is "ninety million, eight hundred nineteen thousand, twenty-one".