2865780 has 120 divisors (see below), whose sum is σ = 9452520. Its totient is φ = 725760.

The previous prime is 2865749. The next prime is 2865787. The reversal of 2865780 is 875682.

2865780 is a `hidden beast` number, since 2 + 86 + 578 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2916 + 2862864 = 54^2 + 1692^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2865787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 46950 + ... + 47010.

It is an arithmetic number, because the mean of its divisors is an integer number (78771).

2^2865780 is an apocalyptic number.

2865780 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 2865780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4726260).

2865780 is an abundant number, since it is smaller than the sum of its proper divisors (6586740).

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

2865780 is a wasteful number, since it uses less digits than its factorization.

2865780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 2865780 is about 1692.8614828154. The cubic root of 2865780 is about 142.0411835846.

The spelling of 2865780 in words is "two million, eight hundred sixty-five thousand, seven hundred eighty".