21122255 has 32 divisors (see below), whose sum is σ = 32030208. Its totient is φ = 12988800.

The previous prime is 21122251. The next prime is 21122267. The reversal of 21122255 is 55222112.

It is a happy number.

It is not a de Polignac number, because 21122255 - 2² = 21122251 is a prime.

It is a super-2 number, since 2×21122255² = 892299312570050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31625 + ... + 32285.

It is an arithmetic number, because the mean of its divisors is an integer number (1000944).

Almost surely, 2^21122255 is an apocalyptic number.

21122255 is a deficient number, since it is larger than the sum of its proper divisors (10907953).

21122255 is a wasteful number, since it uses less digits than its factorization.

21122255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767.

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

The square root of 21122255 is about 4595.8954513783. The cubic root of 21122255 is about 276.4267666056.

Adding to 21122255 its reverse (55222112), we get a palindrome (76344367).

The spelling of 21122255 in words is "twenty-one million, one hundred twenty-two thousand, two hundred fifty-five".