21056426 has 8 divisors (see below), whose sum is σ = 31661280. Its totient is φ = 10502668.

The previous prime is 21056401. The next prime is 21056437. The reversal of 21056426 is 62465012.

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 = 21056395 and 21056404.

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 3 ways as a sum of consecutive naturals, for example, 11726 + ... + 13401.

It is an arithmetic number, because the mean of its divisors is an integer number (3957660).

Almost surely, 2^21056426 is an apocalyptic number.

21056426 is a deficient number, since it is larger than the sum of its proper divisors (10604854).

21056426 is a wasteful number, since it uses less digits than its factorization.

21056426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25548.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 21056426 is about 4588.7281462296. The cubic root of 21056426 is about 276.1392999125.

The spelling of 21056426 in words is "twenty-one million, fifty-six thousand, four hundred twenty-six".