21222125 has 8 divisors (see below), whose sum is σ = 26485368. Its totient is φ = 16977600.

The previous prime is 21222043. The next prime is 21222143. The reversal of 21222125 is 52122212.

It can be written as a sum of positive squares in 4 ways, for example, as 6889 + 21215236 = 83^2 + 4606^2 .

It is not a de Polignac number, because 21222125 - 2¹⁶ = 21156589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84764 + ... + 85013.

It is an arithmetic number, because the mean of its divisors is an integer number (3310671).

Almost surely, 2^21222125 is an apocalyptic number.

21222125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21222125 is a deficient number, since it is larger than the sum of its proper divisors (5263243).

21222125 is an equidigital number, since it uses as much as digits as its factorization.

21222125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169792 (or 169782 counting only the distinct ones).

The product of its digits is 160, while the sum is 17.

The square root of 21222125 is about 4606.7477682200. The cubic root of 21222125 is about 276.8617477058.

Adding to 21222125 its reverse (52122212), we get a palindrome (73344337).

The spelling of 21222125 in words is "twenty-one million, two hundred twenty-two thousand, one hundred twenty-five".