11891287 has 2 divisors, whose sum is σ = 11891288. Its totient is φ = 11891286.

The previous prime is 11891267. The next prime is 11891291. The reversal of 11891287 is 78219811.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11891287 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11891267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5945643 + 5945644.

It is an arithmetic number, because the mean of its divisors is an integer number (5945644).

Almost surely, 2^11891287 is an apocalyptic number.

11891287 is a deficient number, since it is larger than the sum of its proper divisors (1).

11891287 is an equidigital number, since it uses as much as digits as its factorization.

11891287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 37.

The square root of 11891287 is about 3448.3745446224. The cubic root of 11891287 is about 228.2493872716.

The spelling of 11891287 in words is "eleven million, eight hundred ninety-one thousand, two hundred eighty-seven".