21107438 has 16 divisors (see below), whose sum is σ = 36571824. Its totient is φ = 9029760.

The previous prime is 21107417. The next prime is 21107467. The reversal of 21107438 is 83470112.

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, 27845 + ... + 28592.

It is an arithmetic number, because the mean of its divisors is an integer number (2285739).

Almost surely, 2^21107438 is an apocalyptic number.

21107438 is a deficient number, since it is larger than the sum of its proper divisors (15464386).

21107438 is a wasteful number, since it uses less digits than its factorization.

21107438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56467.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21107438 is about 4594.2831867442. The cubic root of 21107438 is about 276.3621148360.

It can be divided in two parts, 211074 and 38, that added together give a palindrome (211112).

The spelling of 21107438 in words is "twenty-one million, one hundred seven thousand, four hundred thirty-eight".