221421255546648 has 96 divisors (see below), whose sum is σ = 564808682188800. Its totient is φ = 72335681368704.

The previous prime is 221421255546643. The next prime is 221421255546649. The reversal of 221421255546648 is 846645552124122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221421255546641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60168361 + ... + 63742247.

It is an arithmetic number, because the mean of its divisors is an integer number (5883423772800).

Almost surely, 2^{221421255546648} 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 221421255546648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282404341094400).

221421255546648 is an abundant number, since it is smaller than the sum of its proper divisors (343387426642152).

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

221421255546648 is a wasteful number, since it uses less digits than its factorization.

221421255546648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3574921 (or 3574864 counting only the distinct ones).

The product of its digits is 36864000, while the sum is 57.

The spelling of 221421255546648 in words is "two hundred twenty-one trillion, four hundred twenty-one billion, two hundred fifty-five million, five hundred forty-six thousand, six hundred forty-eight".