1211212121020 has 192 divisors, whose sum is σ = 2853348083712. Its totient is φ = 428110592000.

The previous prime is 1211212120969. The next prime is 1211212121023. The reversal of 1211212121020 is 201212121121.

It is a junction number, because it is equal to n+sod(n) for n = 1211212120985 and 1211212121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211212121023) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 1287153750 + ... + 1287154690.

It is an arithmetic number, because the mean of its divisors is an integer number (14861187936).

Almost surely, 2^{1211212121020} is an apocalyptic number.

1211212121020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211212121020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1426674041856).

1211212121020 is an abundant number, since it is smaller than the sum of its proper divisors (1642135962692).

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

1211212121020 is a wasteful number, since it uses less digits than its factorization.

1211212121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1732 (or 1730 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1211212121020 its reverse (201212121121), we get a palindrome (1412424242141).

The spelling of 1211212121020 in words is "one trillion, two hundred eleven billion, two hundred twelve million, one hundred twenty-one thousand, twenty".