221512131100 has 144 divisors (see below), whose sum is σ = 527075015040. Its totient is φ = 80304480000.

The previous prime is 221512131091. The next prime is 221512131107. The reversal of 221512131100 is 1131215122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221512131107) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 98404975 + ... + 98407225.

It is an arithmetic number, because the mean of its divisors is an integer number (3660243160).

Almost surely, 2^221512131100 is an apocalyptic number.

221512131100 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 221512131100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263537507520).

221512131100 is an abundant number, since it is smaller than the sum of its proper divisors (305562883940).

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

221512131100 is a wasteful number, since it uses less digits than its factorization.

221512131100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3620 (or 3613 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 19.

Adding to 221512131100 its reverse (1131215122), we get a palindrome (222643346222).

The spelling of 221512131100 in words is "two hundred twenty-one billion, five hundred twelve million, one hundred thirty-one thousand, one hundred".