11817121 has 2 divisors, whose sum is σ = 11817122. Its totient is φ = 11817120.

The previous prime is 11817089. The next prime is 11817133. The reversal of 11817121 is 12171811.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11806096 + 11025 = 3436^2 + 105^2 .

It is an emirp because it is prime and its reverse (12171811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11817121 - 2⁵ = 11817089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11817092 and 11817101.

It is not a weakly prime, because it can be changed into another prime (11817161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5908560 + 5908561.

It is an arithmetic number, because the mean of its divisors is an integer number (5908561).

Almost surely, 2^11817121 is an apocalyptic number.

It is an amenable number.

11817121 is a deficient number, since it is larger than the sum of its proper divisors (1).

11817121 is an equidigital number, since it uses as much as digits as its factorization.

11817121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112, while the sum is 22.

The square root of 11817121 is about 3437.6039620643. The cubic root of 11817121 is about 227.7738665378.

Adding to 11817121 its reverse (12171811), we get a palindrome (23988932).

The spelling of 11817121 in words is "eleven million, eight hundred seventeen thousand, one hundred twenty-one".