2120681 has 4 divisors (see below), whose sum is σ = 2123664. Its totient is φ = 2117700.

The previous prime is 2120653. The next prime is 2120693. The reversal of 2120681 is 1860212.

2120681 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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2120681 - 2¹⁸ = 1858537 is a prime.

It is a super-2 number, since 2×2120681² = 8994575807522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2120611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266 + ... + 2076.

It is an arithmetic number, because the mean of its divisors is an integer number (530916).

2^2120681 is an apocalyptic number.

It is an amenable number.

2120681 is a deficient number, since it is larger than the sum of its proper divisors (2983).

2120681 is a wasteful number, since it uses less digits than its factorization.

2120681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2982.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 2120681 is about 1456.2558154390. The cubic root of 2120681 is about 128.4769195527.

Adding to 2120681 its reverse (1860212), we get a palindrome (3980893).

It can be divided in two parts, 21 and 20681, that added together give a palindrome (20702).

The spelling of 2120681 in words is "two million, one hundred twenty thousand, six hundred eighty-one".