16091391 has 4 divisors (see below), whose sum is σ = 21455192. Its totient is φ = 10727592.

The previous prime is 16091389. The next prime is 16091399. The reversal of 16091391 is 19319061.

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

It is not a de Polignac number, because 16091391 - 2¹ = 16091389 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 (16091399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2681896 + ... + 2681901.

It is an arithmetic number, because the mean of its divisors is an integer number (5363798).

Almost surely, 2^16091391 is an apocalyptic number.

16091391 is a deficient number, since it is larger than the sum of its proper divisors (5363801).

16091391 is an equidigital number, since it uses as much as digits as its factorization.

16091391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5363800.

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 16091391 is about 4011.4076083091. The cubic root of 16091391 is about 252.4630720756.

The spelling of 16091391 in words is "sixteen million, ninety-one thousand, three hundred ninety-one".