1812217440 has 192 divisors, whose sum is σ = 6271437312. Its totient is φ = 436224000.

The previous prime is 1812217427. The next prime is 1812217441. The reversal of 1812217440 is 447122181.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1812217398 and 1812217407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1812217441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 796144 + ... + 798416.

It is an arithmetic number, because the mean of its divisors is an integer number (32663736).

Almost surely, 2^1812217440 is an apocalyptic number.

1812217440 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 1812217440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3135718656).

1812217440 is an abundant number, since it is smaller than the sum of its proper divisors (4459219872).

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

1812217440 is a wasteful number, since it uses less digits than its factorization.

1812217440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2453 (or 2445 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 1812217440 is about 42570.1472865669. The cubic root of 1812217440 is about 1219.1863785928.

The spelling of 1812217440 in words is "one billion, eight hundred twelve million, two hundred seventeen thousand, four hundred forty".