21809226 has 32 divisors (see below), whose sum is σ = 46347840. Its totient is φ = 6822144.

The previous prime is 21809219. The next prime is 21809231. The reversal of 21809226 is 62290812.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21809193 and 21809202.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12036 + ... + 13728.

It is an arithmetic number, because the mean of its divisors is an integer number (1448370).

Almost surely, 2^21809226 is an apocalyptic number.

21809226 is an abundant number, since it is smaller than the sum of its proper divisors (24538614).

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

21809226 is a wasteful number, since it uses less digits than its factorization.

21809226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1830.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 21809226 is about 4670.0349035098. The cubic root of 21809226 is about 279.3916468818.

The spelling of 21809226 in words is "twenty-one million, eight hundred nine thousand, two hundred twenty-six".