13820588721 has 27 divisors (see below), whose sum is σ = 20174660779. Its totient is φ = 9117090672.

The previous prime is 13820588699. The next prime is 13820588731. The reversal of 13820588721 is 12788502831.

The square root of 13820588721 is 117561.

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

It can be written as a sum of positive squares in only one way, i.e., 1619177121 + 12201411600 = 40239^2 + 110460^2 .

It is not a de Polignac number, because 13820588721 - 2¹¹ = 13820586673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13820588731) 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, 52549636 + ... + 52549898.

Almost surely, 2^13820588721 is an apocalyptic number.

13820588721 is the 117561-st square number.

13820588721 is the 58781-st centered octagonal number.

It is an amenable number.

13820588721 is a deficient number, since it is larger than the sum of its proper divisors (6354072058).

13820588721 is an frugal number, since it uses more digits than its factorization.

13820588721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830 (or 415 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 13820588721 in words is "thirteen billion, eight hundred twenty million, five hundred eighty-eight thousand, seven hundred twenty-one".