21722088 has 16 divisors (see below), whose sum is σ = 54305280. Its totient is φ = 7240688.

The previous prime is 21722081. The next prime is 21722093. The reversal of 21722088 is 88022712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722081) 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, 452520 + ... + 452567.

It is an arithmetic number, because the mean of its divisors is an integer number (3394080).

Almost surely, 2^21722088 is an apocalyptic number.

It is an amenable number.

21722088 is an abundant number, since it is smaller than the sum of its proper divisors (32583192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21722088 is a wasteful number, since it uses less digits than its factorization.

21722088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905096 (or 905092 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 21722088 is about 4660.6960853503. The cubic root of 21722088 is about 279.0190503558.

The spelling of 21722088 in words is "twenty-one million, seven hundred twenty-two thousand, eighty-eight".