21121011110020 has 24 divisors (see below), whose sum is σ = 44354256055704. Its totient is φ = 8448379163136.

The previous prime is 21121011110011. The next prime is 21121011110021. The reversal of 21121011110020 is 2001111012112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 66348486724 + 21054662623296 = 257582^2 + 4588536^2 .

It is a super-2 number, since 2×21121011110020² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121011110021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6206604 + ... + 8986876.

It is an arithmetic number, because the mean of its divisors is an integer number (1848094002321).

Almost surely, 2^{21121011110020} is an apocalyptic number.

21121011110020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121011110020 is an abundant number, since it is smaller than the sum of its proper divisors (23233244945684).

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

21121011110020 is a wasteful number, since it uses less digits than its factorization.

21121011110020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3160119 (or 3160117 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21121011110020 its reverse (2001111012112), we get a palindrome (23122122122132).

The spelling of 21121011110020 in words is "twenty-one trillion, one hundred twenty-one billion, eleven million, one hundred ten thousand, twenty".