21228358 has 16 divisors (see below), whose sum is σ = 33768000. Its totient is φ = 9980712.

The previous prime is 21228341. The next prime is 21228371. The reversal of 21228358 is 85382212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3273 + ... + 7291.

It is an arithmetic number, because the mean of its divisors is an integer number (2110500).

Almost surely, 2^21228358 is an apocalyptic number.

21228358 is a deficient number, since it is larger than the sum of its proper divisors (12539642).

21228358 is a wasteful number, since it uses less digits than its factorization.

21228358 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4179.

The product of its digits is 7680, while the sum is 31.

The square root of 21228358 is about 4607.4242261810. The cubic root of 21228358 is about 276.8888500869. Note that the first 4 decimals are identical.

The spelling of 21228358 in words is "twenty-one million, two hundred twenty-eight thousand, three hundred fifty-eight".