21222855 has 12 divisors (see below), whose sum is σ = 36786360. Its totient is φ = 11318832.

The previous prime is 21222847. The next prime is 21222913. The reversal of 21222855 is 55822212.

It is not a de Polignac number, because 21222855 - 2³ = 21222847 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 235765 + ... + 235854.

It is an arithmetic number, because the mean of its divisors is an integer number (3065530).

Almost surely, 2^21222855 is an apocalyptic number.

21222855 is a deficient number, since it is larger than the sum of its proper divisors (15563505).

21222855 is a wasteful number, since it uses less digits than its factorization.

21222855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471630 (or 471627 counting only the distinct ones).

The product of its digits is 3200, while the sum is 27.

The square root of 21222855 is about 4606.8269991394. The cubic root of 21222855 is about 276.8649221721.

The spelling of 21222855 in words is "twenty-one million, two hundred twenty-two thousand, eight hundred fifty-five".