16992391 has 4 divisors (see below), whose sum is σ = 18299512. Its totient is φ = 15685272.

The previous prime is 16992329. The next prime is 16992397. The reversal of 16992391 is 19329961.

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 16992391 - 2⁷ = 16992263 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 (16992397) 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, 653541 + ... + 653566.

It is an arithmetic number, because the mean of its divisors is an integer number (4574878).

Almost surely, 2^16992391 is an apocalyptic number.

16992391 is a deficient number, since it is larger than the sum of its proper divisors (1307121).

16992391 is a wasteful number, since it uses less digits than its factorization.

16992391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307120.

The product of its digits is 26244, while the sum is 40.

The square root of 16992391 is about 4122.1827955587. The cubic root of 16992391 is about 257.0897908279.

The spelling of 16992391 in words is "sixteen million, nine hundred ninety-two thousand, three hundred ninety-one".