1220212121100 has 144 divisors (see below), whose sum is σ = 4035302724096. Its totient is φ = 278873280000.

The previous prime is 1220212121099. The next prime is 1220212121143. The reversal of 1220212121100 is 11212120221.

It is a super-2 number, since 2×1220212121100² (a number of 25 digits) contains 22 as substring.

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 1220212121100.

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 47 ways as a sum of consecutive naturals, for example, 21288480 + ... + 21345720.

It is an arithmetic number, because the mean of its divisors is an integer number (28022935584).

Almost surely, 2^{1220212121100} is an apocalyptic number.

1220212121100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220212121100 is an abundant number, since it is smaller than the sum of its proper divisors (2815090602996).

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

1220212121100 is a wasteful number, since it uses less digits than its factorization.

1220212121100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67416 (or 67409 counting only the distinct ones).

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

Adding to 1220212121100 its reverse (11212120221), we get a palindrome (1231424241321).

The spelling of 1220212121100 in words is "one trillion, two hundred twenty billion, two hundred twelve million, one hundred twenty-one thousand, one hundred".