16699391 has 2 divisors, whose sum is σ = 16699392. Its totient is φ = 16699390.

The previous prime is 16699387. The next prime is 16699393. The reversal of 16699391 is 19399661.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (19399661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16699391 - 2² = 16699387 is a prime.

Together with 16699393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16699393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8349695 + 8349696.

It is an arithmetic number, because the mean of its divisors is an integer number (8349696).

Almost surely, 2^16699391 is an apocalyptic number.

16699391 is a deficient number, since it is larger than the sum of its proper divisors (1).

16699391 is an equidigital number, since it uses as much as digits as its factorization.

16699391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 78732, while the sum is 44.

The square root of 16699391 is about 4086.4888351738. The cubic root of 16699391 is about 255.6035479355.

The spelling of 16699391 in words is "sixteen million, six hundred ninety-nine thousand, three hundred ninety-one".