2857840 has 40 divisors (see below), whose sum is σ = 6718320. Its totient is φ = 1130496.

The previous prime is 2857831. The next prime is 2857849. The reversal of 2857840 is 487582.

It is an interprime number because it is at equal distance from previous prime (2857831) and next prime (2857849).

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 2857796 and 2857805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2857849) 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, 10992 + ... + 11248.

It is an arithmetic number, because the mean of its divisors is an integer number (167958).

2^2857840 is an apocalyptic number.

2857840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2857840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3359160).

2857840 is an abundant number, since it is smaller than the sum of its proper divisors (3860480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2857840 is a wasteful number, since it uses less digits than its factorization.

2857840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409 (or 403 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 34.

The square root of 2857840 is about 1690.5147145174. The cubic root of 2857840 is about 141.9098813236.

The spelling of 2857840 in words is "two million, eight hundred fifty-seven thousand, eight hundred forty".