12511999991 has 2 divisors, whose sum is σ = 12511999992. Its totient is φ = 12511999990.

The previous prime is 12511999967. The next prime is 12512000003. The reversal of 12511999991 is 19999911521.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12511999991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12511999901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6255999995 + 6255999996.

It is an arithmetic number, because the mean of its divisors is an integer number (6255999996).

Almost surely, 2^12511999991 is an apocalyptic number.

12511999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12511999991 is an equidigital number, since it uses as much as digits as its factorization.

12511999991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 590490, while the sum is 56.

The spelling of 12511999991 in words is "twelve billion, five hundred eleven million, nine hundred ninety-nine thousand, nine hundred ninety-one".