16897391 has 4 divisors (see below), whose sum is σ = 19311312. Its totient is φ = 14483472.

The previous prime is 16897381. The next prime is 16897399. The reversal of 16897391 is 19379861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19379861 = 479 ⋅40459.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16897391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16897399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1206950 + ... + 1206963.

It is an arithmetic number, because the mean of its divisors is an integer number (4827828).

Almost surely, 2^16897391 is an apocalyptic number.

16897391 is a deficient number, since it is larger than the sum of its proper divisors (2413921).

16897391 is an equidigital number, since it uses as much as digits as its factorization.

16897391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2413920.

The product of its digits is 81648, while the sum is 44.

The square root of 16897391 is about 4110.6436235704. The cubic root of 16897391 is about 256.6097879998.

The spelling of 16897391 in words is "sixteen million, eight hundred ninety-seven thousand, three hundred ninety-one".