21539226 has 8 divisors (see below), whose sum is σ = 43078464. Its totient is φ = 7179740.

The previous prime is 21539213. The next prime is 21539237. The reversal of 21539226 is 62293512.

It is a sphenic number, since it is the product of 3 distinct primes.

21539226 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21539193 and 21539202.

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 3 ways as a sum of consecutive naturals, for example, 1794930 + ... + 1794941.

It is an arithmetic number, because the mean of its divisors is an integer number (5384808).

Almost surely, 2^21539226 is an apocalyptic number.

21539226 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21539226 is a wasteful number, since it uses less digits than its factorization.

21539226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3589876.

The product of its digits is 6480, while the sum is 30.

The square root of 21539226 is about 4641.0371685648. The cubic root of 21539226 is about 278.2338921501.

The spelling of 21539226 in words is "twenty-one million, five hundred thirty-nine thousand, two hundred twenty-six".