221020100 has 36 divisors (see below), whose sum is σ = 548131584. Its totient is φ = 75778080.

The previous prime is 221020099. The next prime is 221020127. The reversal of 221020100 is 1020122.

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, 157172 + ... + 158571.

Almost surely, 2^221020100 is an apocalyptic number.

221020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221020100 is an abundant number, since it is smaller than the sum of its proper divisors (327111484).

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

221020100 is a wasteful number, since it uses less digits than its factorization.

221020100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315764 (or 315757 counting only the distinct ones).

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

The square root of 221020100 is about 14866.7447681058. The cubic root of 221020100 is about 604.6126883769.

Adding to 221020100 its reverse (1020122), we get a palindrome (222040222).

The spelling of 221020100 in words is "two hundred twenty-one million, twenty thousand, one hundred".