2861800 has 48 divisors (see below), whose sum is σ = 6835500. Its totient is φ = 1113600.

The previous prime is 2861777. The next prime is 2861801. The reversal of 2861800 is 81682.

It can be written as a sum of positive squares in 6 ways, for example, as 617796 + 2244004 = 786^2 + 1498^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2861801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8026 + ... + 8374.

2^2861800 is an apocalyptic number.

2861800 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 2861800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3417750).

2861800 is an abundant number, since it is smaller than the sum of its proper divisors (3973700).

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

2861800 is a wasteful number, since it uses less digits than its factorization.

2861800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 2861800 is about 1691.6855499767. The cubic root of 2861800 is about 141.9753974437.

The spelling of 2861800 in words is "two million, eight hundred sixty-one thousand, eight hundred".