11991139 has 2 divisors, whose sum is σ = 11991140. Its totient is φ = 11991138.

The previous prime is 11991131. The next prime is 11991151. The reversal of 11991139 is 93119911.

It is a weak prime.

It is an emirp because it is prime and its reverse (93119911) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11991139 - 2³ = 11991131 is a prime.

It is not a weakly prime, because it can be changed into another prime (11991131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5995569 + 5995570.

It is an arithmetic number, because the mean of its divisors is an integer number (5995570).

Almost surely, 2^11991139 is an apocalyptic number.

11991139 is a deficient number, since it is larger than the sum of its proper divisors (1).

11991139 is an equidigital number, since it uses as much as digits as its factorization.

11991139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2187, while the sum is 34.

The square root of 11991139 is about 3462.8224037626. The cubic root of 11991139 is about 228.8864828963.

The spelling of 11991139 in words is "eleven million, nine hundred ninety-one thousand, one hundred thirty-nine".