820192321 has 9 divisors (see below), whose sum is σ = 888540579. Its totient is φ = 756756936.

The previous prime is 820192309. The next prime is 820192333. The reversal of 820192321 is 123291028.

The square root of 820192321 is 28639.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (820192309) and next prime (820192333).

It can be written as a sum of positive squares in only one way, i.e., 121330225 + 698862096 = 11015^2 + 26436^2 .

It is a de Polignac number, because none of the positive numbers 2^k-820192321 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 820192321.

It is not an unprimeable number, because it can be changed into a prime (820192301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 371206 + ... + 373408.

It is an arithmetic number, because the mean of its divisors is an integer number (98726731).

Almost surely, 2^820192321 is an apocalyptic number.

820192321 is the 28639-th square number.

820192321 is the 14320-th centered octagonal number.

It is an amenable number.

820192321 is a deficient number, since it is larger than the sum of its proper divisors (68348258).

820192321 is an frugal number, since it uses more digits than its factorization.

820192321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4432 (or 2216 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The cubic root of 820192321 is about 936.0633316201.

The spelling of 820192321 in words is "eight hundred twenty million, one hundred ninety-two thousand, three hundred twenty-one".