1813215121200 has 960 divisors, whose sum is σ = 7788251520000. Its totient is φ = 391402782720.

The previous prime is 1813215121087. The next prime is 1813215121217. The reversal of 1813215121200 is 21215123181.

1813215121200 is a `hidden beast` number, since 1 + 8 + 1 + 3 + 21 + 512 + 120 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 191 ways as a sum of consecutive naturals, for example, 501301792 + ... + 501305408.

It is an arithmetic number, because the mean of its divisors is an integer number (8112762000).

Almost surely, 2^{1813215121200} is an apocalyptic number.

1813215121200 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 1813215121200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3894125760000).

1813215121200 is an abundant number, since it is smaller than the sum of its proper divisors (5975036398800).

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

1813215121200 is a wasteful number, since it uses less digits than its factorization.

1813215121200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4019 (or 4002 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The spelling of 1813215121200 in words is "one trillion, eight hundred thirteen billion, two hundred fifteen million, one hundred twenty-one thousand, two hundred".