221220313020 has 72 divisors (see below), whose sum is σ = 766897089504. Its totient is φ = 50564642688.

The previous prime is 221220312991. The next prime is 221220313021. The reversal of 221220313020 is 20313022122.

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 = 221220312984 and 221220313002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220313021) 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, 87784579 + ... + 87787098.

Almost surely, 2^221220313020 is an apocalyptic number.

221220313020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221220313020 is an abundant number, since it is smaller than the sum of its proper divisors (545676776484).

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

221220313020 is a wasteful number, since it uses less digits than its factorization.

221220313020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175571699 (or 175571694 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 221220313020 its reverse (20313022122), we get a palindrome (241533335142).

The spelling of 221220313020 in words is "two hundred twenty-one billion, two hundred twenty million, three hundred thirteen thousand, twenty".