201821565444 has 48 divisors (see below), whose sum is σ = 472200841728. Its totient is φ = 67090687488.

The previous prime is 201821565443. The next prime is 201821565469. The reversal of 201821565444 is 444565128102.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 201821565396 and 201821565405.

It is not an unprimeable number, because it can be changed into a prime (201821565443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7080429 + ... + 7108875.

It is an arithmetic number, because the mean of its divisors is an integer number (9837517536).

Almost surely, 2^201821565444 is an apocalyptic number.

It is an amenable number.

201821565444 is an abundant number, since it is smaller than the sum of its proper divisors (270379276284).

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

201821565444 is a wasteful number, since it uses less digits than its factorization.

201821565444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30044 (or 30042 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 42.

The spelling of 201821565444 in words is "two hundred one billion, eight hundred twenty-one million, five hundred sixty-five thousand, four hundred forty-four".