21255122 has 24 divisors (see below), whose sum is σ = 37453104. Its totient is φ = 9019752.

The previous prime is 21255107. The next prime is 21255127. The reversal of 21255122 is 22155212.

It is a happy number.

It is a super-2 number, since 2×21255122² = 903560422469768, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21255094 and 21255103.

It is not an unprimeable number, because it can be changed into a prime (21255127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9473 + ... + 11499.

It is an arithmetic number, because the mean of its divisors is an integer number (1560546).

Almost surely, 2^21255122 is an apocalyptic number.

21255122 is a deficient number, since it is larger than the sum of its proper divisors (16197982).

21255122 is a wasteful number, since it uses less digits than its factorization.

21255122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2150 (or 2143 counting only the distinct ones).

The product of its digits is 400, while the sum is 20.

The square root of 21255122 is about 4610.3277540756. The cubic root of 21255122 is about 277.0051652692.

The spelling of 21255122 in words is "twenty-one million, two hundred fifty-five thousand, one hundred twenty-two".