21928418 has 8 divisors (see below), whose sum is σ = 32970240. Its totient is φ = 10938340.

The previous prime is 21928381. The next prime is 21928429. The reversal of 21928418 is 81482912.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11858 + ... + 13581.

It is an arithmetic number, because the mean of its divisors is an integer number (4121280).

Almost surely, 2^21928418 is an apocalyptic number.

21928418 is a deficient number, since it is larger than the sum of its proper divisors (11041822).

21928418 is a wasteful number, since it uses less digits than its factorization.

21928418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25872.

The product of its digits is 9216, while the sum is 35.

The square root of 21928418 is about 4682.7788758386. The cubic root of 21928418 is about 279.8997004703.

The spelling of 21928418 in words is "twenty-one million, nine hundred twenty-eight thousand, four hundred eighteen".