21056826 has 32 divisors (see below), whose sum is σ = 50664960. Its totient is φ = 5699376.

The previous prime is 21056801. The next prime is 21056831. The reversal of 21056826 is 62865012.

It is a junction number, because it is equal to n+sod(n) for n = 21056793 and 21056802.

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 15 ways as a sum of consecutive naturals, for example, 12396 + ... + 13991.

It is an arithmetic number, because the mean of its divisors is an integer number (1583280).

Almost surely, 2^21056826 is an apocalyptic number.

21056826 is an abundant number, since it is smaller than the sum of its proper divisors (29608134).

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

21056826 is a wasteful number, since it uses less digits than its factorization.

21056826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26418.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 21056826 is about 4588.7717310845. The cubic root of 21056826 is about 276.1410484685.

The spelling of 21056826 in words is "twenty-one million, fifty-six thousand, eight hundred twenty-six".