821491792 has 20 divisors (see below), whose sum is σ = 1736335296. Its totient is φ = 373405280.

The previous prime is 821491789. The next prime is 821491817. The reversal of 821491792 is 297194128.

It is a happy number.

821491792 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2333608 + ... + 2333959.

Almost surely, 2^821491792 is an apocalyptic number.

It is an amenable number.

821491792 is an abundant number, since it is smaller than the sum of its proper divisors (914843504).

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

821491792 is a wasteful number, since it uses less digits than its factorization.

821491792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4667586 (or 4667580 counting only the distinct ones).

The product of its digits is 72576, while the sum is 43.

The square root of 821491792 is about 28661.6781085825. The cubic root of 821491792 is about 936.5574211539.

The spelling of 821491792 in words is "eight hundred twenty-one million, four hundred ninety-one thousand, seven hundred ninety-two".