13842781 has 2 divisors, whose sum is σ = 13842782. Its totient is φ = 13842780.

The previous prime is 13842779. The next prime is 13842809. The reversal of 13842781 is 18724831.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13439556 + 403225 = 3666^2 + 635^2 .

It is an emirp because it is prime and its reverse (18724831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13842781 - 2¹ = 13842779 is a prime.

It is a super-2 number, since 2×13842781² = 383245171627922, which contains 22 as substring.

Together with 13842779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13842701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6921390 + 6921391.

It is an arithmetic number, because the mean of its divisors is an integer number (6921391).

Almost surely, 2^13842781 is an apocalyptic number.

It is an amenable number.

13842781 is a deficient number, since it is larger than the sum of its proper divisors (1).

13842781 is an equidigital number, since it uses as much as digits as its factorization.

13842781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 34.

The square root of 13842781 is about 3720.5887974889. The cubic root of 13842781 is about 240.1086371600.

The spelling of 13842781 in words is "thirteen million, eight hundred forty-two thousand, seven hundred eighty-one".