21021222011 has 4 divisors (see below), whose sum is σ = 21229353024. Its totient is φ = 20813091000.

The previous prime is 21021221999. The next prime is 21021222031. The reversal of 21021222011 is 11022212012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021222011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021222031) 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, 104065355 + ... + 104065556.

It is an arithmetic number, because the mean of its divisors is an integer number (5307338256).

Almost surely, 2^21021222011 is an apocalyptic number.

21021222011 is a deficient number, since it is larger than the sum of its proper divisors (208131013).

21021222011 is a wasteful number, since it uses less digits than its factorization.

21021222011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208131012.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21021222011 its reverse (11022212012), we get a palindrome (32043434023).

Subtracting from 21021222011 its reverse (11022212012), we obtain a palindrome (9999009999).

The spelling of 21021222011 in words is "twenty-one billion, twenty-one million, two hundred twenty-two thousand, eleven".