221001102100 has 36 divisors (see below), whose sum is σ = 479614357404. Its totient is φ = 88392705280.

The previous prime is 221001102071. The next prime is 221001102149. The reversal of 221001102100 is 1201100122.

It can be written as a sum of positive squares in 6 ways, for example, as 2422411524 + 218578690576 = 49218^2 + 467524^2 .

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 11 ways as a sum of consecutive naturals, for example, 1129104 + ... + 1310296.

It is an arithmetic number, because the mean of its divisors is an integer number (13322621039).

Almost surely, 2^221001102100 is an apocalyptic number.

221001102100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221001102100 is an abundant number, since it is smaller than the sum of its proper divisors (258613255304).

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

221001102100 is a wasteful number, since it uses less digits than its factorization.

221001102100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193404 (or 193397 counting only the distinct ones).

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

Adding to 221001102100 its reverse (1201100122), we get a palindrome (222202202222).

The spelling of 221001102100 in words is "two hundred twenty-one billion, one million, one hundred two thousand, one hundred".