821942290 has 16 divisors (see below), whose sum is σ = 1593303768. Its totient is φ = 303486336.

The previous prime is 821942281. The next prime is 821942311. The reversal of 821942290 is 92249128.

821942290 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 699020721 + 122921569 = 26439^2 + 11087^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3161187 + ... + 3161446.

Almost surely, 2^821942290 is an apocalyptic number.

821942290 is a deficient number, since it is larger than the sum of its proper divisors (771361478).

821942290 is a wasteful number, since it uses less digits than its factorization.

821942290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6322653.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 821942290 is about 28669.5359222991. The cubic root of 821942290 is about 936.7285894876.

The spelling of 821942290 in words is "eight hundred twenty-one million, nine hundred forty-two thousand, two hundred ninety".