221002100 has 72 divisors (see below), whose sum is σ = 540132096. Its totient is φ = 77760000.

The previous prime is 221002097. The next prime is 221002121. The reversal of 221002100 is 1200122.

221002100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30860 + ... + 37340.

Almost surely, 2^221002100 is an apocalyptic number.

221002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270066048).

221002100 is an abundant number, since it is smaller than the sum of its proper divisors (319129996).

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

221002100 is a wasteful number, since it uses less digits than its factorization.

221002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6537 (or 6530 counting only the distinct ones).

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

The square root of 221002100 is about 14866.1393777941. The cubic root of 221002100 is about 604.5962745999.

Adding to 221002100 its reverse (1200122), we get a palindrome (222202222).

The spelling of 221002100 in words is "two hundred twenty-one million, two thousand, one hundred".