1212111212220 has 96 divisors (see below), whose sum is σ = 3851247052800. Its totient is φ = 316352423232.

The previous prime is 1212111212209. The next prime is 1212111212233. The reversal of 1212111212220 is 222121112121.

1212111212220 is a `hidden beast` number, since 1 + 21 + 211 + 1 + 212 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1212111212193 and 1212111212202.

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 31 ways as a sum of consecutive naturals, for example, 23853880 + ... + 23904639.

It is an arithmetic number, because the mean of its divisors is an integer number (40117156800).

Almost surely, 2^{1212111212220} is an apocalyptic number.

1212111212220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212111212220 is an abundant number, since it is smaller than the sum of its proper divisors (2639135840580).

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

1212111212220 is a wasteful number, since it uses less digits than its factorization.

1212111212220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47758584 (or 47758576 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1212111212220 its reverse (222121112121), we get a palindrome (1434232324341).

The spelling of 1212111212220 in words is "one trillion, two hundred twelve billion, one hundred eleven million, two hundred twelve thousand, two hundred twenty".