221101100020 has 48 divisors (see below), whose sum is σ = 491779865808. Its totient is φ = 83211806720.

The previous prime is 221101099931. The next prime is 221101100041. The reversal of 221101100020 is 20001101122.

It can be written as a sum of positive squares in 8 ways, for example, as 648313444 + 220452786576 = 25462^2 + 469524^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 994194 + ... + 1196086.

It is an arithmetic number, because the mean of its divisors is an integer number (10245413871).

Almost surely, 2^221101100020 is an apocalyptic number.

221101100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221101100020 is an abundant number, since it is smaller than the sum of its proper divisors (270678765788).

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

221101100020 is a wasteful number, since it uses less digits than its factorization.

221101100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205140 (or 205138 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 221101100020 its reverse (20001101122), we get a palindrome (241102201142).

The spelling of 221101100020 in words is "two hundred twenty-one billion, one hundred one million, one hundred thousand, twenty".