16999391 has 4 divisors (see below), whose sum is σ = 17458872. Its totient is φ = 16539912.

The previous prime is 16999373. The next prime is 16999393. The reversal of 16999391 is 19399961.

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

It is a cyclic number.

It is not a de Polignac number, because 16999391 - 2¹⁴ = 16983007 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 (16999393) 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, 229685 + ... + 229758.

It is an arithmetic number, because the mean of its divisors is an integer number (4364718).

Almost surely, 2^16999391 is an apocalyptic number.

16999391 is a deficient number, since it is larger than the sum of its proper divisors (459481).

16999391 is an equidigital number, since it uses as much as digits as its factorization.

16999391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459480.

The product of its digits is 118098, while the sum is 47.

The square root of 16999391 is about 4123.0317728584. The cubic root of 16999391 is about 257.1250886164.

The spelling of 16999391 in words is "sixteen million, nine hundred ninety-nine thousand, three hundred ninety-one".