16969991 has 2 divisors, whose sum is σ = 16969992. Its totient is φ = 16969990.

The previous prime is 16969963. The next prime is 16970003. The reversal of 16969991 is 19996961.

It is a strong prime.

It is an emirp because it is prime and its reverse (19996961) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16969991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16969951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8484995 + 8484996.

It is an arithmetic number, because the mean of its divisors is an integer number (8484996).

Almost surely, 2^16969991 is an apocalyptic number.

16969991 is a deficient number, since it is larger than the sum of its proper divisors (1).

16969991 is an equidigital number, since it uses as much as digits as its factorization.

16969991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 236196, while the sum is 50.

The square root of 16969991 is about 4119.4648924345. The cubic root of 16969991 is about 256.9767727195.

The spelling of 16969991 in words is "sixteen million, nine hundred sixty-nine thousand, nine hundred ninety-one".