10890721 has 4 divisors (see below), whose sum is σ = 10909444. Its totient is φ = 10872000.

The previous prime is 10890713. The next prime is 10890731. The reversal of 10890721 is 12709801.

10890721 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6630625 + 4260096 = 2575^2 + 2064^2 .

It is a cyclic number.

It is not a de Polignac number, because 10890721 - 2³ = 10890713 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 10890721.

It is not an unprimeable number, because it can be changed into a prime (10890701) 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, 8460 + ... + 9661.

It is an arithmetic number, because the mean of its divisors is an integer number (2727361).

Almost surely, 2^10890721 is an apocalyptic number.

It is an amenable number.

10890721 is a deficient number, since it is larger than the sum of its proper divisors (18723).

10890721 is an equidigital number, since it uses as much as digits as its factorization.

10890721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18722.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 10890721 is about 3300.1092406161. The cubic root of 10890721 is about 221.6590890683.

It can be divided in two parts, 10890 and 721, that added together give a palindrome (11611).

The spelling of 10890721 in words is "ten million, eight hundred ninety thousand, seven hundred twenty-one".