221735537121 has 16 divisors (see below), whose sum is σ = 352573277184. Its totient is φ = 121197063504.

The previous prime is 221735537099. The next prime is 221735537141. The reversal of 221735537121 is 121735537122.

It is not a de Polignac number, because 221735537121 - 2⁷ = 221735536993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221735537121.

It is not an unprimeable number, because it can be changed into a prime (221735537141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 229539411 + ... + 229540376.

It is an arithmetic number, because the mean of its divisors is an integer number (22035829824).

Almost surely, 2^221735537121 is an apocalyptic number.

221735537121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221735537121 is a deficient number, since it is larger than the sum of its proper divisors (130837740063).

221735537121 is a wasteful number, since it uses less digits than its factorization.

221735537121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459079820.

The product of its digits is 88200, while the sum is 39.

Subtracting from 221735537121 its reverse (121735537122), we obtain a palindrome (99999999999).

The spelling of 221735537121 in words is "two hundred twenty-one billion, seven hundred thirty-five million, five hundred thirty-seven thousand, one hundred twenty-one".