13165861 has 2 divisors, whose sum is σ = 13165862. Its totient is φ = 13165860.

The previous prime is 13165849. The next prime is 13165883. The reversal of 13165861 is 16856131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11189025 + 1976836 = 3345^2 + 1406^2 .

It is an emirp because it is prime and its reverse (16856131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13165861 - 2¹⁵ = 13133093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13165891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6582930 + 6582931.

It is an arithmetic number, because the mean of its divisors is an integer number (6582931).

Almost surely, 2^13165861 is an apocalyptic number.

It is an amenable number.

13165861 is a deficient number, since it is larger than the sum of its proper divisors (1).

13165861 is an equidigital number, since it uses as much as digits as its factorization.

13165861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 31.

The square root of 13165861 is about 3628.4791579944. The cubic root of 13165861 is about 236.1292323418.

The spelling of 13165861 in words is "thirteen million, one hundred sixty-five thousand, eight hundred sixty-one".