221220202100 has 18 divisors (see below), whose sum is σ = 480047838774. Its totient is φ = 88488080800.

The previous prime is 221220202069. The next prime is 221220202121. The reversal of 221220202100 is 1202022122.

It can be written as a sum of positive squares in 3 ways, for example, as 63735041764 + 157485160336 = 252458^2 + 396844^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1106100911 + ... + 1106101110.

Almost surely, 2^221220202100 is an apocalyptic number.

221220202100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221220202100 is an abundant number, since it is smaller than the sum of its proper divisors (258827636674).

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

221220202100 is a wasteful number, since it uses less digits than its factorization.

221220202100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2212202035 (or 2212202028 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 221220202100 its reverse (1202022122), we get a palindrome (222422224222).

The spelling of 221220202100 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred two thousand, one hundred".