16711991 has 2 divisors, whose sum is σ = 16711992. Its totient is φ = 16711990.

The previous prime is 16711957. The next prime is 16712021. The reversal of 16711991 is 19911761.

It is a strong prime.

It is an emirp because it is prime and its reverse (19911761) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16711991 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 (16711921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8355995 + 8355996.

It is an arithmetic number, because the mean of its divisors is an integer number (8355996).

Almost surely, 2^16711991 is an apocalyptic number.

16711991 is a deficient number, since it is larger than the sum of its proper divisors (1).

16711991 is an equidigital number, since it uses as much as digits as its factorization.

16711991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3402, while the sum is 35.

The square root of 16711991 is about 4088.0302102602. The cubic root of 16711991 is about 255.6678176453.

The spelling of 16711991 in words is "sixteen million, seven hundred eleven thousand, nine hundred ninety-one".