21233890 has 16 divisors (see below), whose sum is σ = 38683008. Its totient is φ = 8390896.

The previous prime is 21233881. The next prime is 21233909. The reversal of 21233890 is 9833212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11962 + ... + 13621.

It is an arithmetic number, because the mean of its divisors is an integer number (2417688).

Almost surely, 2^21233890 is an apocalyptic number.

21233890 is a deficient number, since it is larger than the sum of its proper divisors (17449118).

21233890 is a wasteful number, since it uses less digits than its factorization.

21233890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25673.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21233890 is about 4608.0245225042. The cubic root of 21233890 is about 276.9128999307.

The spelling of 21233890 in words is "twenty-one million, two hundred thirty-three thousand, eight hundred ninety".