1820508872400 has 360 divisors, whose sum is σ = 6718061277720. Its totient is φ = 454947471360.

The previous prime is 1820508872381. The next prime is 1820508872401. The reversal of 1820508872400 is 42788050281.

It is a happy number.

1820508872400 is a `hidden beast` number, since 1 + 8 + 20 + 508 + 87 + 2 + 40 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 491911460496 + 1328597411904 = 701364^2 + 1152648^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820508872401) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 14195766 + ... + 14323434.

It is an arithmetic number, because the mean of its divisors is an integer number (18661281327).

Almost surely, 2^{1820508872400} is an apocalyptic number.

1820508872400 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 1820508872400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3359030638860).

1820508872400 is an abundant number, since it is smaller than the sum of its proper divisors (4897552405320).

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

1820508872400 is a wasteful number, since it uses less digits than its factorization.

1820508872400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127943 (or 127929 counting only the distinct ones).

The product of its (nonzero) digits is 286720, while the sum is 45.

The spelling of 1820508872400 in words is "one trillion, eight hundred twenty billion, five hundred eight million, eight hundred seventy-two thousand, four hundred".