221100000020 has 12 divisors (see below), whose sum is σ = 464310000084. Its totient is φ = 88440000000.

The previous prime is 221100000013. The next prime is 221100000029. The reversal of 221100000020 is 20000001122.

It can be written as a sum of positive squares in 2 ways, for example, as 38054645776 + 183045354244 = 195076^2 + 427838^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221099999953 and 221100000007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100000029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5527499981 + ... + 5527500020.

It is an arithmetic number, because the mean of its divisors is an integer number (38692500007).

Almost surely, 2^221100000020 is an apocalyptic number.

221100000020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221100000020 is an abundant number, since it is smaller than the sum of its proper divisors (243210000064).

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

221100000020 is a wasteful number, since it uses less digits than its factorization.

221100000020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11055000010 (or 11055000008 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 221100000020 its reverse (20000001122), we get a palindrome (241100001142).

The spelling of 221100000020 in words is "two hundred twenty-one billion, one hundred million, twenty", and thus it is an aban number.