11980781 has 2 divisors, whose sum is σ = 11980782. Its totient is φ = 11980780.

The previous prime is 11980777. The next prime is 11980783. The reversal of 11980781 is 18708911.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9060100 + 2920681 = 3010^2 + 1709^2 .

It is a cyclic number.

It is not a de Polignac number, because 11980781 - 2² = 11980777 is a prime.

It is a super-2 number, since 2×11980781² = 287078226739922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 11980783, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11980783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5990390 + 5990391.

It is an arithmetic number, because the mean of its divisors is an integer number (5990391).

Almost surely, 2^11980781 is an apocalyptic number.

It is an amenable number.

11980781 is a deficient number, since it is larger than the sum of its proper divisors (1).

11980781 is an equidigital number, since it uses as much as digits as its factorization.

11980781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 11980781 is about 3461.3264798340. The cubic root of 11980781 is about 228.8205595186.

The spelling of 11980781 in words is "eleven million, nine hundred eighty thousand, seven hundred eighty-one".