11311221287 has 2 divisors, whose sum is σ = 11311221288. Its totient is φ = 11311221286.

The previous prime is 11311221263. The next prime is 11311221307. The reversal of 11311221287 is 78212211311.

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-11311221287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11311221487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5655610643 + 5655610644.

It is an arithmetic number, because the mean of its divisors is an integer number (5655610644).

Almost surely, 2^11311221287 is an apocalyptic number.

11311221287 is a deficient number, since it is larger than the sum of its proper divisors (1).

11311221287 is an equidigital number, since it uses as much as digits as its factorization.

11311221287 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1344, while the sum is 29.

Adding to 11311221287 its reverse (78212211311), we get a palindrome (89523432598).

The spelling of 11311221287 in words is "eleven billion, three hundred eleven million, two hundred twenty-one thousand, two hundred eighty-seven".