2186778 has 32 divisors (see below), whose sum is σ = 5054400. Its totient is φ = 623360.

The previous prime is 2186773. The next prime is 2186791. The reversal of 2186778 is 8776812.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2186773) 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, 148 + ... + 2096.

It is an arithmetic number, because the mean of its divisors is an integer number (157950).

2^2186778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2186778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2527200).

2186778 is an abundant number, since it is smaller than the sum of its proper divisors (2867622).

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

2186778 is a wasteful number, since it uses less digits than its factorization.

2186778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1982.

The product of its digits is 37632, while the sum is 39.

The square root of 2186778 is about 1478.7758450827. The cubic root of 2186778 is about 129.7980691433.

It can be divided in two parts, 21867 and 78, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 2186778 in words is "two million, one hundred eighty-six thousand, seven hundred seventy-eight".