21722673 has 16 divisors (see below), whose sum is σ = 33597440. Its totient is φ = 12226896.

The previous prime is 21722671. The next prime is 21722689. The reversal of 21722673 is 37622712.

It is not a de Polignac number, because 21722673 - 2¹ = 21722671 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21722673.

It is not an unprimeable number, because it can be changed into a prime (21722671) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 6313 + ... + 9126.

It is an arithmetic number, because the mean of its divisors is an integer number (2099840).

Almost surely, 2^21722673 is an apocalyptic number.

It is an amenable number.

21722673 is a deficient number, since it is larger than the sum of its proper divisors (11874767).

21722673 is a wasteful number, since it uses less digits than its factorization.

21722673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15516.

The product of its digits is 7056, while the sum is 30.

The square root of 21722673 is about 4660.7588437936. The cubic root of 21722673 is about 279.0215550978.

The spelling of 21722673 in words is "twenty-one million, seven hundred twenty-two thousand, six hundred seventy-three".