221321222100 has 144 divisors (see below), whose sum is σ = 776189279040. Its totient is φ = 53653622400.

The previous prime is 221321222077. The next prime is 221321222209. The reversal of 221321222100 is 1222123122.

221321222100 is a `hidden beast` number, since 2 + 21 + 321 + 222 + 100 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3696247 + ... + 3755646.

Almost surely, 2^221321222100 is an apocalyptic number.

221321222100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221321222100 is an abundant number, since it is smaller than the sum of its proper divisors (554868056940).

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

221321222100 is a wasteful number, since it uses less digits than its factorization.

221321222100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7451927 (or 7451914 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 221321222100 its reverse (1222123122), we get a palindrome (222543345222).

The spelling of 221321222100 in words is "two hundred twenty-one billion, three hundred twenty-one million, two hundred twenty-two thousand, one hundred".