90731321 has 4 divisors (see below), whose sum is σ = 92269200. Its totient is φ = 89193444.

The previous prime is 90731309. The next prime is 90731323. The reversal of 90731321 is 12313709.

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 90731321 - 2⁶ = 90731257 is a prime.

It is a super-2 number, since 2×90731321² = 16464345220810082, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (90731323) 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, 768851 + ... + 768968.

It is an arithmetic number, because the mean of its divisors is an integer number (23067300).

Almost surely, 2^90731321 is an apocalyptic number.

It is an amenable number.

90731321 is a deficient number, since it is larger than the sum of its proper divisors (1537879).

90731321 is a wasteful number, since it uses less digits than its factorization.

90731321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1537878.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 90731321 is about 9525.2989979318. The cubic root of 90731321 is about 449.3510332679.

The spelling of 90731321 in words is "ninety million, seven hundred thirty-one thousand, three hundred twenty-one".