21908826 has 16 divisors (see below), whose sum is σ = 48686400. Its totient is φ = 7302924.

The previous prime is 21908797. The next prime is 21908827. The reversal of 21908826 is 62880912.

It is not an unprimeable number, because it can be changed into a prime (21908827) by changing a digit.

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, 202806 + ... + 202913.

It is an arithmetic number, because the mean of its divisors is an integer number (3042900).

Almost surely, 2^21908826 is an apocalyptic number.

21908826 is an abundant number, since it is smaller than the sum of its proper divisors (26777574).

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

21908826 is a wasteful number, since it uses less digits than its factorization.

21908826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405730 (or 405724 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 21908826 is about 4680.6864881126. The cubic root of 21908826 is about 279.8163166026.

The spelling of 21908826 in words is "twenty-one million, nine hundred eight thousand, eight hundred twenty-six".