21079926 has 80 divisors (see below), whose sum is σ = 55931040. Its totient is φ = 5806080.

The previous prime is 21079889. The next prime is 21079931. The reversal of 21079926 is 62997012.

It is a Curzon number.

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 39 ways as a sum of consecutive naturals, for example, 32566 + ... + 33206.

It is an arithmetic number, because the mean of its divisors is an integer number (699138).

Almost surely, 2^21079926 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21079926, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27965520).

21079926 is an abundant number, since it is smaller than the sum of its proper divisors (34851114).

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

21079926 is a wasteful number, since it uses less digits than its factorization.

21079926 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 691 (or 682 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 21079926 is about 4591.2880545660. The cubic root of 21079926 is about 276.2419900355.

The spelling of 21079926 in words is "twenty-one million, seventy-nine thousand, nine hundred twenty-six".