2781685857 has 16 divisors (see below), whose sum is σ = 3763444608. Its totient is φ = 1827383040.

The previous prime is 2781685817. The next prime is 2781685859. The reversal of 2781685857 is 7585861872.

It is not a de Polignac number, because 2781685857 - 2⁷ = 2781685729 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2781685797 and 2781685806.

It is not an unprimeable number, because it can be changed into a prime (2781685859) 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, 34932 + ... + 82362.

It is an arithmetic number, because the mean of its divisors is an integer number (235215288).

Almost surely, 2^2781685857 is an apocalyptic number.

It is an amenable number.

2781685857 is a deficient number, since it is larger than the sum of its proper divisors (981758751).

2781685857 is a wasteful number, since it uses less digits than its factorization.

2781685857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47720.

The product of its digits is 7526400, while the sum is 57.

The square root of 2781685857 is about 52741.6899331070. The cubic root of 2781685857 is about 1406.3800402490.

The spelling of 2781685857 in words is "two billion, seven hundred eighty-one million, six hundred eighty-five thousand, eight hundred fifty-seven".