21256926 has 16 divisors (see below), whose sum is σ = 42559104. Its totient is φ = 7078104.

The previous prime is 21256909. The next prime is 21256931. The reversal of 21256926 is 62965212.

It is a Curzon number.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9705 + ... + 11691.

It is an arithmetic number, because the mean of its divisors is an integer number (2659944).

Almost surely, 2^21256926 is an apocalyptic number.

21256926 is an abundant number, since it is smaller than the sum of its proper divisors (21302178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21256926 is a wasteful number, since it uses less digits than its factorization.

21256926 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3775.

The product of its digits is 12960, while the sum is 33.

The square root of 21256926 is about 4610.5233976198. The cubic root of 21256926 is about 277.0130018616.

The spelling of 21256926 in words is "twenty-one million, two hundred fifty-six thousand, nine hundred twenty-six".