21001011001011 has 6 divisors (see below), whose sum is σ = 30334793668140. Its totient is φ = 14000674000668.

The previous prime is 21001011001001. The next prime is 21001011001027. The reversal of 21001011001011 is 11010011010012.

It is not a de Polignac number, because 21001011001011 - 2⁹ = 21001011000499 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 2333445666779 = 21001011001011 / (2 + 1 + 0 + 0 + 1 + 0 + 1 + 1 + 0 + 0 + 1 + 0 + 1 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 21001011000984 and 21001011001002.

It is not an unprimeable number, because it can be changed into a prime (21001011001001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1166722833381 + ... + 1166722833398.

It is an arithmetic number, because the mean of its divisors is an integer number (5055798944690).

Almost surely, 2^{21001011001011} is an apocalyptic number.

21001011001011 is a deficient number, since it is larger than the sum of its proper divisors (9333782667129).

21001011001011 is a wasteful number, since it uses less digits than its factorization.

21001011001011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2333445666785 (or 2333445666782 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

Adding to 21001011001011 its reverse (11010011010012), we get a palindrome (32011022011023).

Subtracting from 21001011001011 its reverse (11010011010012), we obtain a palindrome (9990999990999).

The spelling of 21001011001011 in words is "twenty-one trillion, one billion, eleven million, one thousand, eleven".