11817961 has 2 divisors, whose sum is σ = 11817962. Its totient is φ = 11817960.

The previous prime is 11817959. The next prime is 11817973. The reversal of 11817961 is 16971811.

11817961 is digitally balanced in base 3, 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., 8737936 + 3080025 = 2956^2 + 1755^2 .

It is an emirp because it is prime and its reverse (16971811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11817961 - 2¹ = 11817959 is a prime.

Together with 11817959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11817901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5908980 + 5908981.

It is an arithmetic number, because the mean of its divisors is an integer number (5908981).

Almost surely, 2^11817961 is an apocalyptic number.

It is an amenable number.

11817961 is a deficient number, since it is larger than the sum of its proper divisors (1).

11817961 is an equidigital number, since it uses as much as digits as its factorization.

11817961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 34.

The square root of 11817961 is about 3437.7261380162. The cubic root of 11817961 is about 227.7792633829.

The spelling of 11817961 in words is "eleven million, eight hundred seventeen thousand, nine hundred sixty-one".