221545544455320 has 128 divisors (see below), whose sum is σ = 668150403747840. Its totient is φ = 58766508200960.

The previous prime is 221545544455273. The next prime is 221545544455327. The reversal of 221545544455320 is 23554445545122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221545544455327) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 469784764 + ... + 470256116.

It is an arithmetic number, because the mean of its divisors is an integer number (5219925029280).

Almost surely, 2^{221545544455320} is an apocalyptic number.

221545544455320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221545544455320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334075201873920).

221545544455320 is an abundant number, since it is smaller than the sum of its proper divisors (446604859292520).

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

221545544455320 is a wasteful number, since it uses less digits than its factorization.

221545544455320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492065 (or 492061 counting only the distinct ones).

The product of its (nonzero) digits is 19200000, while the sum is 51.

The spelling of 221545544455320 in words is "two hundred twenty-one trillion, five hundred forty-five billion, five hundred forty-four million, four hundred fifty-five thousand, three hundred twenty".