1212121100220 has 48 divisors (see below), whose sum is σ = 3572567456640. Its totient is φ = 306220067136.

The previous prime is 1212121100219. The next prime is 1212121100237. The reversal of 1212121100220 is 220011212121.

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 1212121100220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 531630922 + ... + 531633201.

It is an arithmetic number, because the mean of its divisors is an integer number (74428488680).

Almost surely, 2^{1212121100220} is an apocalyptic number.

1212121100220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212121100220 is an abundant number, since it is smaller than the sum of its proper divisors (2360446356420).

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

1212121100220 is a wasteful number, since it uses less digits than its factorization.

1212121100220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063264154 (or 1063264152 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1212121100220 its reverse (220011212121), we get a palindrome (1432132312341).

The spelling of 1212121100220 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, one hundred thousand, two hundred twenty".