16993811 has 4 divisors (see below), whose sum is σ = 17080272. Its totient is φ = 16907352.

The previous prime is 16993799. The next prime is 16993817. The reversal of 16993811 is 11839961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11839961 = 7 ⋅1691423.

It is a cyclic number.

It is not a de Polignac number, because 16993811 - 2⁶ = 16993747 is a prime.

It is a super-2 number, since 2×16993811² = 577579224607442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16993817) 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, 42935 + ... + 43328.

It is an arithmetic number, because the mean of its divisors is an integer number (4270068).

Almost surely, 2^16993811 is an apocalyptic number.

16993811 is a deficient number, since it is larger than the sum of its proper divisors (86461).

16993811 is an equidigital number, since it uses as much as digits as its factorization.

16993811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86460.

The product of its digits is 11664, while the sum is 38.

The square root of 16993811 is about 4122.3550308046. The cubic root of 16993811 is about 257.0969520201.

The spelling of 16993811 in words is "sixteen million, nine hundred ninety-three thousand, eight hundred eleven".