201821111912 has 64 divisors (see below), whose sum is σ = 442664663040. Its totient is φ = 84479371200.

The previous prime is 201821111909. The next prime is 201821111941. The reversal of 201821111912 is 219111128102.

It is a super-2 number, since 2×201821111912² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188237 + ... + 662627.

It is an arithmetic number, because the mean of its divisors is an integer number (6916635360).

Almost surely, 2^201821111912 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 201821111912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221332331520).

201821111912 is an abundant number, since it is smaller than the sum of its proper divisors (240843551128).

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

201821111912 is a wasteful number, since it uses less digits than its factorization.

201821111912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474582 (or 474578 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 29.

The spelling of 201821111912 in words is "two hundred one billion, eight hundred twenty-one million, one hundred eleven thousand, nine hundred twelve".