21055208 has 32 divisors (see below), whose sum is σ = 40877760. Its totient is φ = 10160640.

The previous prime is 21055207. The next prime is 21055213. The reversal of 21055208 is 80255012.

It is not an unprimeable number, because it can be changed into a prime (21055207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33053 + ... + 33683.

It is an arithmetic number, because the mean of its divisors is an integer number (1277430).

Almost surely, 2^21055208 is an apocalyptic number.

It is an amenable number.

21055208 is a deficient number, since it is larger than the sum of its proper divisors (19822552).

21055208 is a wasteful number, since it uses less digits than its factorization.

21055208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777 (or 773 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 21055208 is about 4588.5954277971. The cubic root of 21055208 is about 276.1339754231.

The spelling of 21055208 in words is "twenty-one million, fifty-five thousand, two hundred eight".