1212121311220 has 24 divisors (see below), whose sum is σ = 2607539017608. Its totient is φ = 473022950400.

The previous prime is 1212121311199. The next prime is 1212121311221. The reversal of 1212121311220 is 221131212121.

It can be written as a sum of positive squares in 4 ways, for example, as 194012059024 + 1018109252196 = 440468^2 + 1009014^2 .

It is a super-2 number, since 2×1212121311220² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212121311221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 739097541 + ... + 739099180.

It is an arithmetic number, because the mean of its divisors is an integer number (108647459067).

Almost surely, 2^{1212121311220} is an apocalyptic number.

1212121311220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212121311220 is an abundant number, since it is smaller than the sum of its proper divisors (1395417706388).

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

1212121311220 is a wasteful number, since it uses less digits than its factorization.

1212121311220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1478196771 (or 1478196769 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 1212121311220 its reverse (221131212121), we get a palindrome (1433252523341).

Subtracting from 1212121311220 its reverse (221131212121), we obtain a palindrome (990990099099).

The spelling of 1212121311220 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, three hundred eleven thousand, two hundred twenty".