821561226 has 16 divisors (see below), whose sum is σ = 1643888928. Its totient is φ = 273726000.

The previous prime is 821561207. The next prime is 821561243. The reversal of 821561226 is 622165128.

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 7 ways as a sum of consecutive naturals, for example, 17500 + ... + 44151.

It is an arithmetic number, because the mean of its divisors is an integer number (102743058).

Almost surely, 2^821561226 is an apocalyptic number.

821561226 is an abundant number, since it is smaller than the sum of its proper divisors (822327702).

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

821561226 is a wasteful number, since it uses less digits than its factorization.

821561226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63877.

The product of its digits is 11520, while the sum is 33.

The square root of 821561226 is about 28662.8893519129. The cubic root of 821561226 is about 936.5838069302.

The spelling of 821561226 in words is "eight hundred twenty-one million, five hundred sixty-one thousand, two hundred twenty-six".