21109430 has 16 divisors (see below), whose sum is σ = 38054880. Its totient is φ = 8430912.

The previous prime is 21109409. The next prime is 21109441. The reversal of 21109430 is 3490112.

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, 8042 + ... + 10338.

It is an arithmetic number, because the mean of its divisors is an integer number (2378430).

Almost surely, 2^21109430 is an apocalyptic number.

It is a pronic number, being equal to 4594×4595.

21109430 is a deficient number, since it is larger than the sum of its proper divisors (16945450).

21109430 is a wasteful number, since it uses less digits than its factorization.

21109430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3223.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21109430 is about 4594.4999727936. The cubic root of 21109430 is about 276.3708083909.

Adding to 21109430 its reverse (3490112), we get a palindrome (24599542).

The spelling of 21109430 in words is "twenty-one million, one hundred nine thousand, four hundred thirty".