11821961 has 2 divisors, whose sum is σ = 11821962. Its totient is φ = 11821960.

The previous prime is 11821913. The next prime is 11821967. The reversal of 11821961 is 16912811.

11821961 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11526025 + 295936 = 3395^2 + 544^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11821961 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11821967) 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, 5910980 + 5910981.

It is an arithmetic number, because the mean of its divisors is an integer number (5910981).

Almost surely, 2^11821961 is an apocalyptic number.

It is an amenable number.

11821961 is a deficient number, since it is larger than the sum of its proper divisors (1).

11821961 is an equidigital number, since it uses as much as digits as its factorization.

11821961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 29.

The square root of 11821961 is about 3438.3078687052. The cubic root of 11821961 is about 227.8049591375.

The spelling of 11821961 in words is "eleven million, eight hundred twenty-one thousand, nine hundred sixty-one".