21722275 has 6 divisors (see below), whose sum is σ = 26935652. Its totient is φ = 17377800.

The previous prime is 21722269. The next prime is 21722279. The reversal of 21722275 is 57222712.

It is not a de Polignac number, because 21722275 - 2⁷ = 21722147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21722279) 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 5 ways as a sum of consecutive naturals, for example, 434421 + ... + 434470.

Almost surely, 2^21722275 is an apocalyptic number.

21722275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21722275 is a deficient number, since it is larger than the sum of its proper divisors (5213377).

21722275 is an equidigital number, since it uses as much as digits as its factorization.

21722275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868901 (or 868896 counting only the distinct ones).

The product of its digits is 3920, while the sum is 28.

The square root of 21722275 is about 4660.7161466882. The cubic root of 21722275 is about 279.0198510218.

Adding to 21722275 its reverse (57222712), we get a palindrome (78944987).

The spelling of 21722275 in words is "twenty-one million, seven hundred twenty-two thousand, two hundred seventy-five".