1865365538400 has 1728 divisors, whose sum is σ = 8817335654400. Its totient is φ = 359930511360.

The previous prime is 1865365538357. The next prime is 1865365538401. The reversal of 1865365538400 is 48355635681.

It is a happy number.

1865365538400 is a `hidden beast` number, since 1 + 8 + 6 + 5 + 3 + 6 + 553 + 84 + 0 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1865365538401) 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 287 ways as a sum of consecutive naturals, for example, 361012617 + ... + 361017783.

It is an arithmetic number, because the mean of its divisors is an integer number (5102624800).

Almost surely, 2^{1865365538400} is an apocalyptic number.

1865365538400 is a gapful number since it is divisible by the number (10) 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 1865365538400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4408667827200).

1865365538400 is an abundant number, since it is smaller than the sum of its proper divisors (6951970116000).

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

1865365538400 is a wasteful number, since it uses less digits than its factorization.

1865365538400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5261 (or 5245 counting only the distinct ones).

The product of its (nonzero) digits is 10368000, while the sum is 54.

The spelling of 1865365538400 in words is "one trillion, eight hundred sixty-five billion, three hundred sixty-five million, five hundred thirty-eight thousand, four hundred".