16681611 has 4 divisors (see below), whose sum is σ = 22242152. Its totient is φ = 11121072.

The previous prime is 16681597. The next prime is 16681633. The reversal of 16681611 is 11618661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11618661 = 3 ⋅3872887.

It is not a de Polignac number, because 16681611 - 2⁵ = 16681579 is a prime.

It is a super-2 number, since 2×16681611² = 556552291110642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16681661) 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, 2780266 + ... + 2780271.

It is an arithmetic number, because the mean of its divisors is an integer number (5560538).

Almost surely, 2^16681611 is an apocalyptic number.

16681611 is a deficient number, since it is larger than the sum of its proper divisors (5560541).

16681611 is an equidigital number, since it uses as much as digits as its factorization.

16681611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5560540.

The product of its digits is 1728, while the sum is 30.

The square root of 16681611 is about 4084.3127940940. The cubic root of 16681611 is about 255.5128012142.

The spelling of 16681611 in words is "sixteen million, six hundred eighty-one thousand, six hundred eleven".