2102781 has 8 divisors (see below), whose sum is σ = 2968704. Its totient is φ = 1319360.

The previous prime is 2102777. The next prime is 2102783. The reversal of 2102781 is 1872012.

2102781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2102781 - 2² = 2102777 is a prime.

It is a super-2 number, since 2×2102781² = 8843375867922, which contains 22 as substring.

2102781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2102783) 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 7 ways as a sum of consecutive naturals, for example, 20565 + ... + 20666.

It is an arithmetic number, because the mean of its divisors is an integer number (371088).

2^2102781 is an apocalyptic number.

It is an amenable number.

2102781 is a deficient number, since it is larger than the sum of its proper divisors (865923).

2102781 is a wasteful number, since it uses less digits than its factorization.

2102781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41251.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 2102781 is about 1450.0968933144. The cubic root of 2102781 is about 128.1144199870.

Adding to 2102781 its reverse (1872012), we get a palindrome (3974793).

The spelling of 2102781 in words is "two million, one hundred two thousand, seven hundred eighty-one".