13870443721 has 2 divisors, whose sum is σ = 13870443722. Its totient is φ = 13870443720.

The previous prime is 13870443689. The next prime is 13870443751. The reversal of 13870443721 is 12734407831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10337805625 + 3532638096 = 101675^2 + 59436^2 .

It is a cyclic number.

It is not a de Polignac number, because 13870443721 - 2⁵ = 13870443689 is a prime.

It is not a weakly prime, because it can be changed into another prime (13870443751) 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 as a sum of consecutive naturals, namely, 6935221860 + 6935221861.

It is an arithmetic number, because the mean of its divisors is an integer number (6935221861).

Almost surely, 2^13870443721 is an apocalyptic number.

It is an amenable number.

13870443721 is a deficient number, since it is larger than the sum of its proper divisors (1).

13870443721 is an equidigital number, since it uses as much as digits as its factorization.

13870443721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112896, while the sum is 40.

The spelling of 13870443721 in words is "thirteen billion, eight hundred seventy million, four hundred forty-three thousand, seven hundred twenty-one".