21000121101011 has 4 divisors (see below), whose sum is σ = 22615515031872. Its totient is φ = 19384727170152.

The previous prime is 21000121100971. The next prime is 21000121101041. The reversal of 21000121101011 is 11010112100012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21000121101011 - 2¹⁰ = 21000121099987 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000121100983 and 21000121101001.

It is not an unprimeable number, because it can be changed into a prime (21000121101041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807696965411 + ... + 807696965436.

It is an arithmetic number, because the mean of its divisors is an integer number (5653878757968).

Almost surely, 2^{21000121101011} is an apocalyptic number.

21000121101011 is a deficient number, since it is larger than the sum of its proper divisors (1615393930861).

21000121101011 is a wasteful number, since it uses less digits than its factorization.

21000121101011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615393930860.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21000121101011 its reverse (11010112100012), we get a palindrome (32010233201023).

Subtracting from 21000121101011 its reverse (11010112100012), we obtain a palindrome (9990009000999).

It can be divided in two parts, 2100012 and 1101011, that multiplied together give a palindrome (2312136312132).

The spelling of 21000121101011 in words is "twenty-one trillion, one hundred twenty-one million, one hundred one thousand, eleven".