21103406 has 8 divisors (see below), whose sum is σ = 31787184. Its totient is φ = 10507680.

The previous prime is 21103403. The next prime is 21103441. The reversal of 21103406 is 60430112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21410 + ... + 22373.

It is an arithmetic number, because the mean of its divisors is an integer number (3973398).

Almost surely, 2^21103406 is an apocalyptic number.

21103406 is a deficient number, since it is larger than the sum of its proper divisors (10683778).

21103406 is a wasteful number, since it uses less digits than its factorization.

21103406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44026.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21103406 is about 4593.8443595751. The cubic root of 21103406 is about 276.3445165687.

Adding to 21103406 its reverse (60430112), we get a palindrome (81533518).

The spelling of 21103406 in words is "twenty-one million, one hundred three thousand, four hundred six".