21722842 has 8 divisors (see below), whose sum is σ = 32841216. Its totient is φ = 10775772.

The previous prime is 21722837. The next prime is 21722851. The reversal of 21722842 is 24822712.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21722842.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42508 + ... + 43015.

It is an arithmetic number, because the mean of its divisors is an integer number (4105152).

Almost surely, 2^21722842 is an apocalyptic number.

21722842 is a deficient number, since it is larger than the sum of its proper divisors (11118374).

21722842 is a wasteful number, since it uses less digits than its factorization.

21722842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85652.

The product of its digits is 3584, while the sum is 28.

The square root of 21722842 is about 4660.7769738532. The cubic root of 21722842 is about 279.0222786816.

The spelling of 21722842 in words is "twenty-one million, seven hundred twenty-two thousand, eight hundred forty-two".