13971817 has 2 divisors, whose sum is σ = 13971818. Its totient is φ = 13971816.

The previous prime is 13971809. The next prime is 13971851. The reversal of 13971817 is 71817931.

13971817 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10086976 + 3884841 = 3176^2 + 1971^2 .

It is an emirp because it is prime and its reverse (71817931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13971817 - 2³ = 13971809 is a prime.

It is not a weakly prime, because it can be changed into another prime (13971887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6985908 + 6985909.

It is an arithmetic number, because the mean of its divisors is an integer number (6985909).

Almost surely, 2^13971817 is an apocalyptic number.

It is an amenable number.

13971817 is a deficient number, since it is larger than the sum of its proper divisors (1).

13971817 is an equidigital number, since it uses as much as digits as its factorization.

13971817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10584, while the sum is 37.

The square root of 13971817 is about 3737.8893777104. The cubic root of 13971817 is about 240.8523914894.

It can be divided in two parts, 13 and 971817, that multiplied together give a palindrome (12633621).

The spelling of 13971817 in words is "thirteen million, nine hundred seventy-one thousand, eight hundred seventeen".