1821801638196 has 48 divisors (see below), whose sum is σ = 4724238662080. Its totient is φ = 607132311840.

The previous prime is 1821801638119. The next prime is 1821801638207. The reversal of 1821801638196 is 6918361081281.

It is a happy number.

1821801638196 is a `hidden beast` number, since 1 + 82 + 180 + 1 + 6 + 381 + 9 + 6 = 666.

It is a super-2 number, since 2×1821801638196² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1384615 + ... + 2358126.

Almost surely, 2^{1821801638196} is an apocalyptic number.

It is an amenable number.

1821801638196 is an abundant number, since it is smaller than the sum of its proper divisors (2902437023884).

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

1821801638196 is a wasteful number, since it uses less digits than its factorization.

1821801638196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3747261 (or 3747253 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 54.

The spelling of 1821801638196 in words is "one trillion, eight hundred twenty-one billion, eight hundred one million, six hundred thirty-eight thousand, one hundred ninety-six".