16988691 has 4 divisors (see below), whose sum is σ = 22651592. Its totient is φ = 11325792.

The previous prime is 16988681. The next prime is 16988707. The reversal of 16988691 is 19688961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19688961 = 3 ⋅6562987.

It is not a de Polignac number, because 16988691 - 2⁵ = 16988659 is a prime.

16988691 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16988691.

It is not an unprimeable number, because it can be changed into a prime (16988681) 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, 2831446 + ... + 2831451.

It is an arithmetic number, because the mean of its divisors is an integer number (5662898).

Almost surely, 2^16988691 is an apocalyptic number.

16988691 is a deficient number, since it is larger than the sum of its proper divisors (5662901).

16988691 is an equidigital number, since it uses as much as digits as its factorization.

16988691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5662900.

The product of its digits is 186624, while the sum is 48.

The square root of 16988691 is about 4121.7339797711. The cubic root of 16988691 is about 257.0711295091.

The spelling of 16988691 in words is "sixteen million, nine hundred eighty-eight thousand, six hundred ninety-one".