21233390 has 16 divisors (see below), whose sum is σ = 38942208. Its totient is φ = 8332896.

The previous prime is 21233389. The next prime is 21233411. The reversal of 21233390 is 9333212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19502 + ... + 20561.

It is an arithmetic number, because the mean of its divisors is an integer number (2433888).

Almost surely, 2^21233390 is an apocalyptic number.

21233390 is a deficient number, since it is larger than the sum of its proper divisors (17708818).

21233390 is a wasteful number, since it uses less digits than its factorization.

21233390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40123.

The product of its (nonzero) digits is 972, while the sum is 23.

The square root of 21233390 is about 4607.9702690013. The cubic root of 21233390 is about 276.9107264000.

The spelling of 21233390 in words is "twenty-one million, two hundred thirty-three thousand, three hundred ninety".