11947811 has 2 divisors, whose sum is σ = 11947812. Its totient is φ = 11947810.

The previous prime is 11947807. The next prime is 11947847. The reversal of 11947811 is 11874911.

It is a weak prime.

It is an emirp because it is prime and its reverse (11874911) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11947811 - 2² = 11947807 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11947801) 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, 5973905 + 5973906.

It is an arithmetic number, because the mean of its divisors is an integer number (5973906).

Almost surely, 2^11947811 is an apocalyptic number.

11947811 is a deficient number, since it is larger than the sum of its proper divisors (1).

11947811 is an equidigital number, since it uses as much as digits as its factorization.

11947811 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 32.

The square root of 11947811 is about 3456.5605737496. The cubic root of 11947811 is about 228.6104690197.

Subtracting from 11947811 its reverse (11874911), we obtain a square (72900 = 270²).

The spelling of 11947811 in words is "eleven million, nine hundred forty-seven thousand, eight hundred eleven".