11991013 has 2 divisors, whose sum is σ = 11991014. Its totient is φ = 11991012.

The previous prime is 11991011. The next prime is 11991019. The reversal of 11991013 is 31019911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7656289 + 4334724 = 2767^2 + 2082^2 .

It is a cyclic number.

It is not a de Polignac number, because 11991013 - 2¹ = 11991011 is a prime.

Together with 11991011, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11991011) 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, 5995506 + 5995507.

It is an arithmetic number, because the mean of its divisors is an integer number (5995507).

Almost surely, 2^11991013 is an apocalyptic number.

It is an amenable number.

11991013 is a deficient number, since it is larger than the sum of its proper divisors (1).

11991013 is an equidigital number, since it uses as much as digits as its factorization.

11991013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 243, while the sum is 25.

The square root of 11991013 is about 3462.8042104630. The cubic root of 11991013 is about 228.8856811988.

The spelling of 11991013 in words is "eleven million, nine hundred ninety-one thousand, thirteen".