221000100 has 72 divisors (see below), whose sum is σ = 667248960. Its totient is φ = 56369280.

The previous prime is 221000071. The next prime is 221000107. The reversal of 221000100 is 1000122.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is not an unprimeable number, because it can be changed into a prime (221000107) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9115 + ... + 22914.

Almost surely, 2^221000100 is an apocalyptic number.

221000100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221000100 is an abundant number, since it is smaller than the sum of its proper divisors (446248860).

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

221000100 is a wasteful number, since it uses less digits than its factorization.

221000100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32069 (or 32062 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 221000100 is about 14866.0721106821. The cubic root of 221000100 is about 604.5944507919.

Adding to 221000100 its reverse (1000122), we get a palindrome (222000222).

The spelling of 221000100 in words is "two hundred twenty-one million, one hundred", and thus it is an aban number.