221021121100 has 72 divisors (see below), whose sum is σ = 519105490400. Its totient is φ = 81197614080.

The previous prime is 221021121049. The next prime is 221021121137. The reversal of 221021121100 is 1121120122.

It is a Harshad number since it is a multiple of its sum of digits (13).

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, 168477 + ... + 685876.

Almost surely, 2^221021121100 is an apocalyptic number.

221021121100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021121100 is an abundant number, since it is smaller than the sum of its proper divisors (298084369300).

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

221021121100 is a wasteful number, since it uses less digits than its factorization.

221021121100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 854579 (or 854572 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 221021121100 its reverse (1121120122), we get a palindrome (222142241222).

The spelling of 221021121100 in words is "two hundred twenty-one billion, twenty-one million, one hundred twenty-one thousand, one hundred".