2111681 has 8 divisors (see below), whose sum is σ = 2481024. Its totient is φ = 1771920.

The previous prime is 2111677. The next prime is 2111713. The reversal of 2111681 is 1861112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2111681 - 2² = 2111677 is a prime.

It is a super-2 number, since 2×2111681² = 8918393291522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2113681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7241 + ... + 7526.

It is an arithmetic number, because the mean of its divisors is an integer number (310128).

2^2111681 is an apocalyptic number.

It is an amenable number.

2111681 is a deficient number, since it is larger than the sum of its proper divisors (369343).

2111681 is a wasteful number, since it uses less digits than its factorization.

2111681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14791.

The product of its digits is 96, while the sum is 20.

The square root of 2111681 is about 1453.1624134969. The cubic root of 2111681 is about 128.2949132568.

Adding to 2111681 its reverse (1861112), we get a palindrome (3972793).

The spelling of 2111681 in words is "two million, one hundred eleven thousand, six hundred eighty-one".