11778491 has 2 divisors, whose sum is σ = 11778492. Its totient is φ = 11778490.

The previous prime is 11778479. The next prime is 11778493. The reversal of 11778491 is 19487711.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11778491 is a prime.

It is a Sophie Germain prime.

Together with 11778493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11778493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5889245 + 5889246.

It is an arithmetic number, because the mean of its divisors is an integer number (5889246).

Almost surely, 2^11778491 is an apocalyptic number.

11778491 is a deficient number, since it is larger than the sum of its proper divisors (1).

11778491 is an equidigital number, since it uses as much as digits as its factorization.

11778491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 38.

The square root of 11778491 is about 3431.9806234884. The cubic root of 11778491 is about 227.5253990883.

The spelling of 11778491 in words is "eleven million, seven hundred seventy-eight thousand, four hundred ninety-one".