21021210011 has 4 divisors (see below), whose sum is σ = 21035235000. Its totient is φ = 21007185024.

The previous prime is 21021209983. The next prime is 21021210029. The reversal of 21021210011 is 11001212012.

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 21021210011 - 2¹⁸ = 21020947867 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021209974 and 21021210001.

It is not an unprimeable number, because it can be changed into a prime (21021210071) 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, 7010246 + ... + 7013243.

It is an arithmetic number, because the mean of its divisors is an integer number (5258808750).

Almost surely, 2^21021210011 is an apocalyptic number.

21021210011 is a deficient number, since it is larger than the sum of its proper divisors (14024989).

21021210011 is a wasteful number, since it uses less digits than its factorization.

21021210011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14024988.

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

Adding to 21021210011 its reverse (11001212012), we get a palindrome (32022422023).

The spelling of 21021210011 in words is "twenty-one billion, twenty-one million, two hundred ten thousand, eleven".