21406726 has 8 divisors (see below), whose sum is σ = 35029224. Its totient is φ = 9730320.

The previous prime is 21406717. The next prime is 21406729. The reversal of 21406726 is 62760412.

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

It is a junction number, because it is equal to n+sod(n) for n = 21406694 and 21406703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21406729) 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, 486495 + ... + 486538.

It is an arithmetic number, because the mean of its divisors is an integer number (4378653).

Almost surely, 2^21406726 is an apocalyptic number.

21406726 is a deficient number, since it is larger than the sum of its proper divisors (13622498).

21406726 is a wasteful number, since it uses less digits than its factorization.

21406726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973046.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21406726 is about 4626.7403212197. The cubic root of 21406726 is about 277.6621934168.

The spelling of 21406726 in words is "twenty-one million, four hundred six thousand, seven hundred twenty-six".