221240242128 has 80 divisors (see below), whose sum is σ = 577681061760. Its totient is φ = 72956118528.

The previous prime is 221240242127. The next prime is 221240242141. The reversal of 221240242128 is 821242042122.

221240242128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 221240242095 and 221240242104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221240242121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3352426 + ... + 3417782.

It is an arithmetic number, because the mean of its divisors is an integer number (7221013272).

Almost surely, 2^221240242128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221240242128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (288840530880).

221240242128 is an abundant number, since it is smaller than the sum of its proper divisors (356440819632).

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

221240242128 is a wasteful number, since it uses less digits than its factorization.

221240242128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66124 (or 66118 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 30.

The spelling of 221240242128 in words is "two hundred twenty-one billion, two hundred forty million, two hundred forty-two thousand, one hundred twenty-eight".