1821803412 has 192 divisors, whose sum is σ = 5382881280. Its totient is φ = 471398400.

The previous prime is 1821803411. The next prime is 1821803441. The reversal of 1821803412 is 2143081281.

It is a self number, because there is not a number n which added to its sum of digits gives 1821803412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821803411) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1222764 + ... + 1224252.

It is an arithmetic number, because the mean of its divisors is an integer number (28035840).

Almost surely, 2^1821803412 is an apocalyptic number.

1821803412 is a gapful number since it is divisible by the number (12) 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 1821803412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2691440640).

1821803412 is an abundant number, since it is smaller than the sum of its proper divisors (3561077868).

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

1821803412 is a wasteful number, since it uses less digits than its factorization.

1821803412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1574 (or 1572 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 1821803412 is about 42682.5890967265. The cubic root of 1821803412 is about 1221.3322837071.

Adding to 1821803412 its reverse (2143081281), we get a palindrome (3964884693).

The spelling of 1821803412 in words is "one billion, eight hundred twenty-one million, eight hundred three thousand, four hundred twelve".