221231311020 has 192 divisors, whose sum is σ = 699719086080. Its totient is φ = 58021920000.

The previous prime is 221231311001. The next prime is 221231311031. The reversal of 221231311020 is 20113132122.

221231311020 is a `hidden beast` number, since 221 + 2 + 313 + 110 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 221231310984 and 221231311002.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8222109 + ... + 8248971.

It is an arithmetic number, because the mean of its divisors is an integer number (3644370240).

Almost surely, 2^221231311020 is an apocalyptic number.

221231311020 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 221231311020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349859543040).

221231311020 is an abundant number, since it is smaller than the sum of its proper divisors (478487775060).

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

221231311020 is a wasteful number, since it uses less digits than its factorization.

221231311020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27133 (or 27125 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 221231311020 its reverse (20113132122), we get a palindrome (241344443142).

The spelling of 221231311020 in words is "two hundred twenty-one billion, two hundred thirty-one million, three hundred eleven thousand, twenty".