21888722 has 8 divisors (see below), whose sum is σ = 34561200. Its totient is φ = 10368324.

The previous prime is 21888721. The next prime is 21888731. The reversal of 21888722 is 22788812.

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

It is a Harshad number since it is a multiple of its sum of digits (38), and also a Moran number because the ratio is a prime number: 576019 = 21888722 / (2 + 1 + 8 + 8 + 8 + 7 + 2 + 2).

It is not an unprimeable number, because it can be changed into a prime (21888721) 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, 287972 + ... + 288047.

It is an arithmetic number, because the mean of its divisors is an integer number (4320150).

Almost surely, 2^21888722 is an apocalyptic number.

21888722 is a deficient number, since it is larger than the sum of its proper divisors (12672478).

21888722 is a wasteful number, since it uses less digits than its factorization.

21888722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576040.

The product of its digits is 28672, while the sum is 38.

The square root of 21888722 is about 4678.5384469939. The cubic root of 21888722 is about 279.7307019623.

The spelling of 21888722 in words is "twenty-one million, eight hundred eighty-eight thousand, seven hundred twenty-two".