2840781 has 8 divisors (see below), whose sum is σ = 3841344. Its totient is φ = 1867040.

The previous prime is 2840779. The next prime is 2840801. The reversal of 2840781 is 1870482.

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 2840781 - 2¹ = 2840779 is a prime.

It is a super-2 number, since 2×2840781² = 16140073379922, which contains 22 as substring.

2840781 is a modest number, since divided by 781 gives 284 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2840731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6456 + ... + 6881.

It is an arithmetic number, because the mean of its divisors is an integer number (480168).

2^2840781 is an apocalyptic number.

It is an amenable number.

2840781 is a deficient number, since it is larger than the sum of its proper divisors (1000563).

2840781 is a wasteful number, since it uses less digits than its factorization.

2840781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13411.

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 2840781 is about 1685.4616578255. The cubic root of 2840781 is about 141.6269551130.

Subtracting from 2840781 its reverse (1870482), we obtain a cube (970299 = 99³).

The spelling of 2840781 in words is "two million, eight hundred forty thousand, seven hundred eighty-one".