1211212220020 has 96 divisors (see below), whose sum is σ = 2929645555200. Its totient is φ = 415998633600.

The previous prime is 1211212219981. The next prime is 1211212220027. The reversal of 1211212220020 is 200222121121.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1211212219976 and 1211212220003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211212220027) 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, 945871 + ... + 1821289.

It is an arithmetic number, because the mean of its divisors is an integer number (30517141200).

Almost surely, 2^{1211212220020} is an apocalyptic number.

1211212220020 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 1211212220020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1464822777600).

1211212220020 is an abundant number, since it is smaller than the sum of its proper divisors (1718433335180).

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

1211212220020 is a wasteful number, since it uses less digits than its factorization.

1211212220020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875789 (or 875787 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1211212220020 its reverse (200222121121), we get a palindrome (1411434341141).

The spelling of 1211212220020 in words is "one trillion, two hundred eleven billion, two hundred twelve million, two hundred twenty thousand, twenty".