13872354642721 has 9 divisors (see below), whose sum is σ = 14030310395161. Its totient is φ = 13716157728064.

The previous prime is 13872354642691. The next prime is 13872354642781. The reversal of 13872354642721 is 12724645327831.

The square root of 13872354642721 is 3724561.

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 12519148321 + 13859835494400 = 111889^2 + 3722880^2 .

It is not a de Polignac number, because 13872354642721 - 2³⁵ = 13837994904353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13872354642781) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 331465005 + ... + 331506853.

Almost surely, 2^{13872354642721} is an apocalyptic number.

13872354642721 is the 3724561-st square number.

13872354642721 is the 1862281-st centered octagonal number.

It is an amenable number.

13872354642721 is a deficient number, since it is larger than the sum of its proper divisors (157955752440).

13872354642721 is an frugal number, since it uses more digits than its factorization.

13872354642721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83876 (or 41938 counting only the distinct ones).

The product of its digits is 13547520, while the sum is 55.

The spelling of 13872354642721 in words is "thirteen trillion, eight hundred seventy-two billion, three hundred fifty-four million, six hundred forty-two thousand, seven hundred twenty-one".