2105781 has 16 divisors (see below), whose sum is σ = 2940288. Its totient is φ = 1339200.

The previous prime is 2105767. The next prime is 2105809. The reversal of 2105781 is 1875012.

It is not a de Polignac number, because 2105781 - 2⁶ = 2105717 is a prime.

It is a super-2 number, since 2×2105781² = 8868627239922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6616 + ... + 6926.

It is an arithmetic number, because the mean of its divisors is an integer number (183768).

2^2105781 is an apocalyptic number.

It is an amenable number.

2105781 is a deficient number, since it is larger than the sum of its proper divisors (834507).

2105781 is a wasteful number, since it uses less digits than its factorization.

2105781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412.

The product of its (nonzero) digits is 560, while the sum is 24.

The square root of 2105781 is about 1451.1309382685. The cubic root of 2105781 is about 128.1753172188.

The spelling of 2105781 in words is "two million, one hundred five thousand, seven hundred eighty-one".