1211000020020 has 144 divisors (see below), whose sum is σ = 4342896754560. Its totient is φ = 267255168768.

The previous prime is 1211000020007. The next prime is 1211000020057. The reversal of 1211000020020 is 200200001121.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1211000019984 and 1211000020011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16534342 + ... + 16607421.

It is an arithmetic number, because the mean of its divisors is an integer number (30159005240).

Almost surely, 2^{1211000020020} is an apocalyptic number.

1211000020020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211000020020 is an abundant number, since it is smaller than the sum of its proper divisors (3131896734540).

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

1211000020020 is a wasteful number, since it uses less digits than its factorization.

1211000020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33141814 (or 33141809 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1211000020020 its reverse (200200001121), we get a palindrome (1411200021141).

The spelling of 1211000020020 in words is "one trillion, two hundred eleven billion, twenty thousand, twenty".