16111681 has 4 divisors (see below), whose sum is σ = 16127152. Its totient is φ = 16096212.

The previous prime is 16111679. The next prime is 16111709. The reversal of 16111681 is 18611161.

16111681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18611161 = 61 ⋅305101.

It is a cyclic number.

It is not a de Polignac number, because 16111681 - 2¹ = 16111679 is a prime.

It is a super-2 number, since 2×16111681² = 519172529291522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16121681) 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, 6051 + ... + 8296.

It is an arithmetic number, because the mean of its divisors is an integer number (4031788).

Almost surely, 2^16111681 is an apocalyptic number.

It is an amenable number.

16111681 is a deficient number, since it is larger than the sum of its proper divisors (15471).

16111681 is a wasteful number, since it uses less digits than its factorization.

16111681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15470.

The product of its digits is 288, while the sum is 25.

The square root of 16111681 is about 4013.9358490140. The cubic root of 16111681 is about 252.5691396457.

The spelling of 16111681 in words is "sixteen million, one hundred eleven thousand, six hundred eighty-one".