20121100220 has 48 divisors (see below), whose sum is σ = 45863021568. Its totient is φ = 7370818560.

The previous prime is 20121100217. The next prime is 20121100267. The reversal of 20121100220 is 2200112102.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 271661 + ... + 337700.

It is an arithmetic number, because the mean of its divisors is an integer number (955479616).

Almost surely, 2^20121100220 is an apocalyptic number.

20121100220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121100220 is an abundant number, since it is smaller than the sum of its proper divisors (25741921348).

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

20121100220 is a wasteful number, since it uses less digits than its factorization.

20121100220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609510 (or 609508 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20121100220 its reverse (2200112102), we get a palindrome (22321212322).

The spelling of 20121100220 in words is "twenty billion, one hundred twenty-one million, one hundred thousand, two hundred twenty".