821397929 has 8 divisors (see below), whose sum is σ = 899919072. Its totient is φ = 743518240.

The previous prime is 821397901. The next prime is 821397937. The reversal of 821397929 is 929793128.

821397929 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 821397929 - 2⁸ = 821397673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821397329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157679 + ... + 162804.

It is an arithmetic number, because the mean of its divisors is an integer number (112489884).

Almost surely, 2^821397929 is an apocalyptic number.

It is an amenable number.

821397929 is a deficient number, since it is larger than the sum of its proper divisors (78521143).

821397929 is a wasteful number, since it uses less digits than its factorization.

821397929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320727.

The product of its digits is 489888, while the sum is 50.

The square root of 821397929 is about 28660.0406315134. The cubic root of 821397929 is about 936.5217496928.

The spelling of 821397929 in words is "eight hundred twenty-one million, three hundred ninety-seven thousand, nine hundred twenty-nine".