21424790 has 24 divisors (see below), whose sum is σ = 39160368. Its totient is φ = 8439440.

The previous prime is 21424787. The next prime is 21424829. The reversal of 21424790 is 9742412.

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 11 ways as a sum of consecutive naturals, for example, 68735 + ... + 69045.

It is an arithmetic number, because the mean of its divisors is an integer number (1631682).

Almost surely, 2^21424790 is an apocalyptic number.

21424790 is a deficient number, since it is larger than the sum of its proper divisors (17735578).

21424790 is an equidigital number, since it uses as much as digits as its factorization.

21424790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 21424790 is about 4628.6920398748. The cubic root of 21424790 is about 277.7402729216.

The spelling of 21424790 in words is "twenty-one million, four hundred twenty-four thousand, seven hundred ninety".