221640543061 has 12 divisors (see below), whose sum is σ = 258744303180. Its totient is φ = 189301519680.

The previous prime is 221640543049. The next prime is 221640543097. The reversal of 221640543061 is 160345046122.

It can be written as a sum of positive squares in 2 ways, for example, as 93275268100 + 128365274961 = 305410^2 + 358281^2 .

It is not a de Polignac number, because 221640543061 - 2¹¹ = 221640541013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221640543001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8034766 + ... + 8062303.

It is an arithmetic number, because the mean of its divisors is an integer number (21562025265).

Almost surely, 2^221640543061 is an apocalyptic number.

It is an amenable number.

221640543061 is a deficient number, since it is larger than the sum of its proper divisors (37103760119).

221640543061 is a wasteful number, since it uses less digits than its factorization.

221640543061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16097364 (or 16097357 counting only the distinct ones).

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

Adding to 221640543061 its reverse (160345046122), we get a palindrome (381985589183).

The spelling of 221640543061 in words is "two hundred twenty-one billion, six hundred forty million, five hundred forty-three thousand, sixty-one".