1866404736 has 384 divisors, whose sum is σ = 6644851200. Its totient is φ = 491065344.

The previous prime is 1866404719. The next prime is 1866404777. The reversal of 1866404736 is 6374046681.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a junction number, because it is equal to n+sod(n) for n = 1866404691 and 1866404700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5378515 + ... + 5378861.

It is an arithmetic number, because the mean of its divisors is an integer number (17304300).

Almost surely, 2^1866404736 is an apocalyptic number.

1866404736 is a gapful number since it is divisible by the number (16) 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 1866404736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3322425600).

1866404736 is an abundant number, since it is smaller than the sum of its proper divisors (4778446464).

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

1866404736 is a wasteful number, since it uses less digits than its factorization.

1866404736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The square root of 1866404736 is about 43201.9066245924. The cubic root of 1866404736 is about 1231.2189066985.

The spelling of 1866404736 in words is "one billion, eight hundred sixty-six million, four hundred four thousand, seven hundred thirty-six".