221235542824081 has 4 divisors (see below), whose sum is σ = 225942682033152. Its totient is φ = 216528403615012.

The previous prime is 221235542824039. The next prime is 221235542824091. The reversal of 221235542824081 is 180428245532122.

It is the 6072281-st star number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221235542824081 - 2¹¹ = 221235542822033 is a prime.

It is a super-2 number, since 2×221235542824081² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221235542824091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2353569604465 + ... + 2353569604558.

It is an arithmetic number, because the mean of its divisors is an integer number (56485670508288).

Almost surely, 2^{221235542824081} is an apocalyptic number.

221235542824081 is the 9407137-th centered pentagonal number.

It is an amenable number.

221235542824081 is a deficient number, since it is larger than the sum of its proper divisors (4707139209071).

221235542824081 is an equidigital number, since it uses as much as digits as its factorization.

221235542824081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4707139209070.

The product of its (nonzero) digits is 2457600, while the sum is 49.

The spelling of 221235542824081 in words is "two hundred twenty-one trillion, two hundred thirty-five billion, five hundred forty-two million, eight hundred twenty-four thousand, eighty-one".