821930305 has 16 divisors (see below), whose sum is σ = 1137565440. Its totient is φ = 558436032.

The previous prime is 821930303. The next prime is 821930309. The reversal of 821930305 is 503039128.

It is a happy number.

821930305 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 821930305 - 2¹ = 821930303 is a prime.

It is not an unprimeable number, because it can be changed into a prime (821930303) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103909 + ... + 111538.

It is an arithmetic number, because the mean of its divisors is an integer number (71097840).

Almost surely, 2^821930305 is an apocalyptic number.

It is an amenable number.

821930305 is a deficient number, since it is larger than the sum of its proper divisors (315635135).

821930305 is a wasteful number, since it uses less digits than its factorization.

821930305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215568.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 821930305 is about 28669.3269017604. The cubic root of 821930305 is about 936.7240365537.

The spelling of 821930305 in words is "eight hundred twenty-one million, nine hundred thirty thousand, three hundred five".