821912422 has 4 divisors (see below), whose sum is σ = 1232868636. Its totient is φ = 410956210.

The previous prime is 821912411. The next prime is 821912423. The reversal of 821912422 is 224219128.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821912423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205478104 + ... + 205478107.

It is an arithmetic number, because the mean of its divisors is an integer number (308217159).

Almost surely, 2^821912422 is an apocalyptic number.

821912422 is a deficient number, since it is larger than the sum of its proper divisors (410956214).

821912422 is a wasteful number, since it uses less digits than its factorization.

821912422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410956213.

The product of its digits is 4608, while the sum is 31.

The square root of 821912422 is about 28669.0150162157. The cubic root of 821912422 is about 936.7172429698.

The spelling of 821912422 in words is "eight hundred twenty-one million, nine hundred twelve thousand, four hundred twenty-two".