1813040891550 has 768 divisors, whose sum is σ = 6301036707840. Its totient is φ = 374191488000.

The previous prime is 1813040891513. The next prime is 1813040891603. The reversal of 1813040891550 is 551980403181.

1813040891550 is a `hidden beast` number, since 1 + 8 + 1 + 3 + 0 + 4 + 0 + 8 + 91 + 550 = 666.

It is a super-2 number, since 2×1813040891550² (a number of 25 digits) contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 1813040891496 and 1813040891505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 276248569 + ... + 276255131.

It is an arithmetic number, because the mean of its divisors is an integer number (8204474880).

Almost surely, 2^{1813040891550} is an apocalyptic number.

1813040891550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1813040891550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3150518353920).

1813040891550 is an abundant number, since it is smaller than the sum of its proper divisors (4487995816290).

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

1813040891550 is a wasteful number, since it uses less digits than its factorization.

1813040891550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6686 (or 6675 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 45.

The spelling of 1813040891550 in words is "one trillion, eight hundred thirteen billion, forty million, eight hundred ninety-one thousand, five hundred fifty".