22890721 has 16 divisors (see below), whose sum is σ = 27907200. Its totient is φ = 18328320.

The previous prime is 22890713. The next prime is 22890737. The reversal of 22890721 is 12709822.

It is a cyclic number.

It is not a de Polignac number, because 22890721 - 2³ = 22890713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (22890701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17086 + ... + 18376.

It is an arithmetic number, because the mean of its divisors is an integer number (1744200).

Almost surely, 2^22890721 is an apocalyptic number.

It is an amenable number.

22890721 is a deficient number, since it is larger than the sum of its proper divisors (5016479).

22890721 is a wasteful number, since it uses less digits than its factorization.

22890721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1464.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 22890721 is about 4784.4248348156. The cubic root of 22890721 is about 283.9355843128.

The spelling of 22890721 in words is "twenty-two million, eight hundred ninety thousand, seven hundred twenty-one".