1211212021020 has 48 divisors (see below), whose sum is σ = 3394180546848. Its totient is φ = 322724454400.

The previous prime is 1211212021007. The next prime is 1211212021021. The reversal of 1211212021020 is 201202121121.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211212021021) 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 15 ways as a sum of consecutive naturals, for example, 8220681 + ... + 8366720.

It is an arithmetic number, because the mean of its divisors is an integer number (70712094726).

Almost surely, 2^{1211212021020} is an apocalyptic number.

1211212021020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211212021020 is an abundant number, since it is smaller than the sum of its proper divisors (2182968525828).

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

1211212021020 is a wasteful number, since it uses less digits than its factorization.

1211212021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16588630 (or 16588628 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1211212021020 its reverse (201202121121), we get a palindrome (1412414142141).

The spelling of 1211212021020 in words is "one trillion, two hundred eleven billion, two hundred twelve million, twenty-one thousand, twenty".