1821783961836 has 96 divisors (see below), whose sum is σ = 4768941804480. Its totient is φ = 601400328192.

The previous prime is 1821783961759. The next prime is 1821783961901. The reversal of 1821783961836 is 6381693871281.

1821783961836 is a `hidden beast` number, since 1 + 8 + 2 + 1 + 7 + 8 + 3 + 9 + 618 + 3 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4612090 + ... + 4991486.

It is an arithmetic number, because the mean of its divisors is an integer number (49676477130).

Almost surely, 2^{1821783961836} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1821783961836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2384470902240).

1821783961836 is an abundant number, since it is smaller than the sum of its proper divisors (2947157842644).

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

1821783961836 is a wasteful number, since it uses less digits than its factorization.

1821783961836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379840 (or 379832 counting only the distinct ones).

The product of its digits is 20901888, while the sum is 63.

The spelling of 1821783961836 in words is "one trillion, eight hundred twenty-one billion, seven hundred eighty-three million, nine hundred sixty-one thousand, eight hundred thirty-six".