1866376728 has 80 divisors (see below), whose sum is σ = 5236478280. Its totient is φ = 621067392.

The previous prime is 1866376727. The next prime is 1866376741. The reversal of 1866376728 is 8276736681.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1866376727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 440476 + ... + 444692.

Almost surely, 2^1866376728 is an apocalyptic number.

1866376728 is a gapful number since it is divisible by the number (18) 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 1866376728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2618239140).

1866376728 is an abundant number, since it is smaller than the sum of its proper divisors (3370101552).

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

1866376728 is a wasteful number, since it uses less digits than its factorization.

1866376728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4918 (or 4905 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The square root of 1866376728 is about 43201.5824710160. The cubic root of 1866376728 is about 1231.2127479500.

The spelling of 1866376728 in words is "one billion, eight hundred sixty-six million, three hundred seventy-six thousand, seven hundred twenty-eight".