221221201024 has 64 divisors (see below), whose sum is σ = 460758104640. Its totient is φ = 105598411776.

The previous prime is 221221200997. The next prime is 221221201039. The reversal of 221221201024 is 420102122122.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 221221200992 and 221221201010.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1467874 + ... + 1611550.

It is an arithmetic number, because the mean of its divisors is an integer number (7199345385).

Almost surely, 2^221221201024 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 221221201024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230379052320).

221221201024 is an abundant number, since it is smaller than the sum of its proper divisors (239536903616).

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

221221201024 is a wasteful number, since it uses less digits than its factorization.

221221201024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144237 (or 144225 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 221221201024 its reverse (420102122122), we get a palindrome (641323323146).

The spelling of 221221201024 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred one thousand, twenty-four".