21122355 has 24 divisors (see below), whose sum is σ = 34645968. Its totient is φ = 10984896.

The previous prime is 21122351. The next prime is 21122359. The reversal of 21122355 is 55322112.

It is an interprime number because it is at equal distance from previous prime (21122351) and next prime (21122359).

It is not a de Polignac number, because 21122355 - 2² = 21122351 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21122351) 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 23 ways as a sum of consecutive naturals, for example, 129504 + ... + 129666.

It is an arithmetic number, because the mean of its divisors is an integer number (1443582).

Almost surely, 2^21122355 is an apocalyptic number.

21122355 is a deficient number, since it is larger than the sum of its proper divisors (13523613).

21122355 is an equidigital number, since it uses as much as digits as its factorization.

21122355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387 (or 224 counting only the distinct ones).

The product of its digits is 600, while the sum is 21.

The square root of 21122355 is about 4595.9063306382. The cubic root of 21122355 is about 276.4272028380.

Adding to 21122355 its reverse (55322112), we get a palindrome (76444467).

The spelling of 21122355 in words is "twenty-one million, one hundred twenty-two thousand, three hundred fifty-five".