20121211111020 has 48 divisors (see below), whose sum is σ = 56473213963488. Its totient is φ = 5352911262720.

The previous prime is 20121211111019. The next prime is 20121211111063. The reversal of 20121211111020 is 2011111212102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 398256829 + ... + 398307348.

It is an arithmetic number, because the mean of its divisors is an integer number (1176525290906).

Almost surely, 2^{20121211111020} is an apocalyptic number.

20121211111020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121211111020 is an abundant number, since it is smaller than the sum of its proper divisors (36352002852468).

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

20121211111020 is a wasteful number, since it uses less digits than its factorization.

20121211111020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796564610 (or 796564608 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 20121211111020 its reverse (2011111212102), we get a palindrome (22132322323122).

The spelling of 20121211111020 in words is "twenty trillion, one hundred twenty-one billion, two hundred eleven million, one hundred eleven thousand, twenty".