21011212122020 has 24 divisors (see below), whose sum is σ = 46445837323200. Its totient is φ = 7962143540832.

The previous prime is 21011212122007. The next prime is 21011212122037. The reversal of 21011212122020 is 2022121211012.

It is a self number, because there is not a number n which added to its sum of digits gives 21011212122020.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27646331360 + ... + 27646332119.

It is an arithmetic number, because the mean of its divisors is an integer number (1935243221800).

Almost surely, 2^{21011212122020} is an apocalyptic number.

21011212122020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011212122020 is an abundant number, since it is smaller than the sum of its proper divisors (25434625201180).

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

21011212122020 is a wasteful number, since it uses less digits than its factorization.

21011212122020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55292663507 (or 55292663505 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21011212122020 its reverse (2022121211012), we get a palindrome (23033333333032).

The spelling of 21011212122020 in words is "twenty-one trillion, eleven billion, two hundred twelve million, one hundred twenty-two thousand, twenty".