11717921 has 2 divisors, whose sum is σ = 11717922. Its totient is φ = 11717920.

The previous prime is 11717903. The next prime is 11717933. The reversal of 11717921 is 12971711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11662225 + 55696 = 3415^2 + 236^2 .

It is a cyclic number.

It is not a de Polignac number, because 11717921 - 2¹⁰ = 11716897 is a prime.

It is not a weakly prime, because it can be changed into another prime (11717941) 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, 5858960 + 5858961.

It is an arithmetic number, because the mean of its divisors is an integer number (5858961).

Almost surely, 2^11717921 is an apocalyptic number.

It is an amenable number.

11717921 is a deficient number, since it is larger than the sum of its proper divisors (1).

11717921 is an equidigital number, since it uses as much as digits as its factorization.

11717921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 882, while the sum is 29.

The square root of 11717921 is about 3423.1448990658. The cubic root of 11717921 is about 227.1347179138.

The spelling of 11717921 in words is "eleven million, seven hundred seventeen thousand, nine hundred twenty-one".