820971321 has 8 divisors (see below), whose sum is σ = 1094761920. Its totient is φ = 547247472.

The previous prime is 820971317. The next prime is 820971373. The reversal of 820971321 is 123179028.

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

It is not a de Polignac number, because 820971321 - 2² = 820971317 is a prime.

It is not an unprimeable number, because it can be changed into a prime (820971311) 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, 34075 + ... + 52943.

It is an arithmetic number, because the mean of its divisors is an integer number (136845240).

Almost surely, 2^820971321 is an apocalyptic number.

It is an amenable number.

820971321 is a deficient number, since it is larger than the sum of its proper divisors (273790599).

820971321 is a wasteful number, since it uses less digits than its factorization.

820971321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33375.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 820971321 is about 28652.5971074177. The cubic root of 820971321 is about 936.3595883969.

The spelling of 820971321 in words is "eight hundred twenty million, nine hundred seventy-one thousand, three hundred twenty-one".