16696991 has 4 divisors (see below), whose sum is σ = 17575800. Its totient is φ = 15818184.

The previous prime is 16696987. The next prime is 16696997. The reversal of 16696991 is 19969661.

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

It is not a de Polignac number, because 16696991 - 2² = 16696987 is a prime.

16696991 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16696997) 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, 439376 + ... + 439413.

It is an arithmetic number, because the mean of its divisors is an integer number (4393950).

Almost surely, 2^16696991 is an apocalyptic number.

16696991 is a deficient number, since it is larger than the sum of its proper divisors (878809).

16696991 is an equidigital number, since it uses as much as digits as its factorization.

16696991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878808.

The product of its digits is 157464, while the sum is 47.

The square root of 16696991 is about 4086.1951739974. The cubic root of 16696991 is about 255.5913024209.

The spelling of 16696991 in words is "sixteen million, six hundred ninety-six thousand, nine hundred ninety-one".