21133390 has 16 divisors (see below), whose sum is σ = 38434032. Its totient is φ = 8365824.

The previous prime is 21133381. The next prime is 21133403. The reversal of 21133390 is 9333112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9924 + ... + 11863.

It is an arithmetic number, because the mean of its divisors is an integer number (2402127).

Almost surely, 2^21133390 is an apocalyptic number.

21133390 is a deficient number, since it is larger than the sum of its proper divisors (17300642).

21133390 is a wasteful number, since it uses less digits than its factorization.

21133390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21891.

The product of its (nonzero) digits is 486, while the sum is 22.

The square root of 21133390 is about 4597.1066987835. The cubic root of 21133390 is about 276.4753326217.

The spelling of 21133390 in words is "twenty-one million, one hundred thirty-three thousand, three hundred ninety".