2187864 has 64 divisors (see below), whose sum is σ = 6950400. Its totient is φ = 624672.

The previous prime is 2187863. The next prime is 2187877. The reversal of 2187864 is 4687812.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2187863) 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, 789 + ... + 2235.

It is an arithmetic number, because the mean of its divisors is an integer number (108600).

2^2187864 is an apocalyptic number.

2187864 is a gapful number since it is divisible by the number (24) 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 2187864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3475200).

2187864 is an abundant number, since it is smaller than the sum of its proper divisors (4762536).

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

2187864 is a wasteful number, since it uses less digits than its factorization.

2187864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1469 (or 1459 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 2187864 is about 1479.1429951158. The cubic root of 2187864 is about 129.8195524054.

It can be divided in two parts, 2187 and 864, that multiplied together give a 5-th power (1889568 = 18⁵).

The spelling of 2187864 in words is "two million, one hundred eighty-seven thousand, eight hundred sixty-four".