21011202011 has 4 divisors (see below), whose sum is σ = 21036246000. Its totient is φ = 20986158024.

The previous prime is 21011202007. The next prime is 21011202013. The reversal of 21011202011 is 11020211012.

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 21011202011 - 2² = 21011202007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011201983 and 21011202001.

It is not an unprimeable number, because it can be changed into a prime (21011202013) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 12520736 + ... + 12522413.

It is an arithmetic number, because the mean of its divisors is an integer number (5259061500).

Almost surely, 2^21011202011 is an apocalyptic number.

21011202011 is a deficient number, since it is larger than the sum of its proper divisors (25043989).

21011202011 is an equidigital number, since it uses as much as digits as its factorization.

21011202011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25043988.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21011202011 its reverse (11020211012), we get a palindrome (32031413023).

Subtracting from 21011202011 its reverse (11020211012), we obtain a palindrome (9990990999).

The spelling of 21011202011 in words is "twenty-one billion, eleven million, two hundred two thousand, eleven".