1212121222220 has 96 divisors (see below), whose sum is σ = 2629179907200. Its totient is φ = 469188761600.

The previous prime is 1212121222199. The next prime is 1212121222229. The reversal of 1212121222220 is 222221212121.

It is a super-2 number, since 2×1212121222220² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1212121222192 and 1212121222201.

It is not an unprimeable number, because it can be changed into a prime (1212121222229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28135256 + ... + 28178304.

It is an arithmetic number, because the mean of its divisors is an integer number (27387290700).

Almost surely, 2^{1212121222220} is an apocalyptic number.

1212121222220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212121222220 is an abundant number, since it is smaller than the sum of its proper divisors (1417058684980).

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

1212121222220 is a wasteful number, since it uses less digits than its factorization.

1212121222220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43475 (or 43473 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 1212121222220 its reverse (222221212121), we get a palindrome (1434342434341).

It can be divided in two parts, 1212121 and 222220, that added together give a palindrome (1434341).

The spelling of 1212121222220 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty".