19220772321 has 27 divisors (see below), whose sum is σ = 28556842041. Its totient is φ = 12457545984.

The previous prime is 19220772301. The next prime is 19220772367. The reversal of 19220772321 is 12327702291.

The square root of 19220772321 is 138639.

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

It can be written as a sum of positive squares in 4 ways, for example, as 2433942225 + 16786830096 = 49335^2 + 129564^2 .

It is a de Polignac number, because none of the positive numbers 2^k-19220772321 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19220772301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 15388305 + ... + 15389553.

Almost surely, 2^19220772321 is an apocalyptic number.

19220772321 is the 138639-th square number.

19220772321 is the 69320-th centered octagonal number.

It is an amenable number.

19220772321 is a deficient number, since it is larger than the sum of its proper divisors (9336069720).

19220772321 is an frugal number, since it uses more digits than its factorization.

19220772321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2578 (or 1289 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

Multiplying 19220772321 by its sum of digits (36), we get a square (691947803556 = 831834²).

The spelling of 19220772321 in words is "nineteen billion, two hundred twenty million, seven hundred seventy-two thousand, three hundred twenty-one".