201643521640 has 64 divisors (see below), whose sum is σ = 494991984960. Its totient is φ = 73317688320.

The previous prime is 201643521631. The next prime is 201643521641. The reversal of 201643521640 is 46125346102.

201643521640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×201643521640² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 201643521596 and 201643521605.

It is not an unprimeable number, because it can be changed into a prime (201643521641) by changing a digit.

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, 6750979 + ... + 6780781.

It is an arithmetic number, because the mean of its divisors is an integer number (7734249765).

Almost surely, 2^201643521640 is an apocalyptic number.

201643521640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201643521640 is an abundant number, since it is smaller than the sum of its proper divisors (293348463320).

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

201643521640 is a wasteful number, since it uses less digits than its factorization.

201643521640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45202 (or 45198 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

Adding to 201643521640 its reverse (46125346102), we get a palindrome (247768867742).

The spelling of 201643521640 in words is "two hundred one billion, six hundred forty-three million, five hundred twenty-one thousand, six hundred forty".