2112781 has 12 divisors (see below), whose sum is σ = 2447200. Its totient is φ = 1817640.

The previous prime is 2112779. The next prime is 2112793. The reversal of 2112781 is 1872112.

It is not a de Polignac number, because 2112781 - 2¹ = 2112779 is a prime.

It is a super-2 number, since 2×2112781² = 8927687107922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2112751) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1840 + ... + 2758.

2^2112781 is an apocalyptic number.

It is an amenable number.

2112781 is a deficient number, since it is larger than the sum of its proper divisors (334419).

2112781 is a wasteful number, since it uses less digits than its factorization.

2112781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 960 (or 949 counting only the distinct ones).

The product of its digits is 224, while the sum is 22.

The square root of 2112781 is about 1453.5408490992. The cubic root of 2112781 is about 128.3171861770.

Adding to 2112781 its reverse (1872112), we get a palindrome (3984893).

It can be divided in two parts, 211 and 2781, that added together give a palindrome (2992).

The spelling of 2112781 in words is "two million, one hundred twelve thousand, seven hundred eighty-one".