16197591 has 4 divisors (see below), whose sum is σ = 21596792. Its totient is φ = 10798392.

The previous prime is 16197581. The next prime is 16197611. The reversal of 16197591 is 19579161.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 16197591 - 2¹⁵ = 16164823 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 (16197521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2699596 + ... + 2699601.

It is an arithmetic number, because the mean of its divisors is an integer number (5399198).

Almost surely, 2^16197591 is an apocalyptic number.

16197591 is a deficient number, since it is larger than the sum of its proper divisors (5399201).

16197591 is an equidigital number, since it uses as much as digits as its factorization.

16197591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5399200.

The product of its digits is 17010, while the sum is 39.

The square root of 16197591 is about 4024.6230879425. The cubic root of 16197591 is about 253.0172568127.

The spelling of 16197591 in words is "sixteen million, one hundred ninety-seven thousand, five hundred ninety-one".