13161861 has 24 divisors (see below), whose sum is σ = 19872216. Its totient is φ = 8386560.

The previous prime is 13161857. The next prime is 13161881. The reversal of 13161861 is 16816131.

It can be written as a sum of positive squares in 4 ways, for example, as 245025 + 12916836 = 495^2 + 3594^2 .

It is not a de Polignac number, because 13161861 - 2² = 13161857 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13161881) 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 in 23 ways as a sum of consecutive naturals, for example, 19221 + ... + 19893.

It is an arithmetic number, because the mean of its divisors is an integer number (828009).

Almost surely, 2^13161861 is an apocalyptic number.

It is an amenable number.

13161861 is a deficient number, since it is larger than the sum of its proper divisors (6710355).

13161861 is a wasteful number, since it uses less digits than its factorization.

13161861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773 (or 770 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 13161861 is about 3627.9279210039. The cubic root of 13161861 is about 236.1053166354.

Adding to 13161861 its reverse (16816131), we get a palindrome (29977992).

The spelling of 13161861 in words is "thirteen million, one hundred sixty-one thousand, eight hundred sixty-one".