221222012100 has 144 divisors (see below), whose sum is σ = 664148408448. Its totient is φ = 56806133760.

The previous prime is 221222012083. The next prime is 221222012117. The reversal of 221222012100 is 1210222122.

It is an interprime number because it is at equal distance from previous prime (221222012083) and next prime (221222012117).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 221222012100.

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, 973969 + ... + 1179431.

Almost surely, 2^221222012100 is an apocalyptic number.

221222012100 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 221222012100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332074204224).

221222012100 is an abundant number, since it is smaller than the sum of its proper divisors (442926396348).

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

221222012100 is a wasteful number, since it uses less digits than its factorization.

221222012100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205614 (or 205607 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221222012100 its reverse (1210222122), we get a palindrome (222432234222).

The spelling of 221222012100 in words is "two hundred twenty-one billion, two hundred twenty-two million, twelve thousand, one hundred".