221100020 has 12 divisors (see below), whose sum is σ = 464310084. Its totient is φ = 88440000.

The previous prime is 221099999. The next prime is 221100037. The reversal of 221100020 is 20001122.

It can be written as a sum of positive squares in 2 ways, for example, as 60621796 + 160478224 = 7786^2 + 12668^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221099980 and 221100007.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5527481 + ... + 5527520.

It is an arithmetic number, because the mean of its divisors is an integer number (38692507).

Almost surely, 2^221100020 is an apocalyptic number.

221100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221100020 is an abundant number, since it is smaller than the sum of its proper divisors (243210064).

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

221100020 is a wasteful number, since it uses less digits than its factorization.

221100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11055010 (or 11055008 counting only the distinct ones).

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

The square root of 221100020 is about 14869.4324034241. The cubic root of 221100020 is about 604.6855547859.

Adding to 221100020 its reverse (20001122), we get a palindrome (241101142).

The spelling of 221100020 in words is "two hundred twenty-one million, one hundred thousand, twenty".