21012221011 has 8 divisors (see below), whose sum is σ = 22831616000. Its totient is φ = 19264174920.

The previous prime is 21012220969. The next prime is 21012221047. The reversal of 21012221011 is 11012221012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21012221011 - 2¹¹ = 21012218963 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012220982 and 21012221000.

It is not an unprimeable number, because it can be changed into a prime (21012221311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17836611 + ... + 17837788.

It is an arithmetic number, because the mean of its divisors is an integer number (2853952000).

Almost surely, 2^21012221011 is an apocalyptic number.

21012221011 is a deficient number, since it is larger than the sum of its proper divisors (1819394989).

21012221011 is a wasteful number, since it uses less digits than its factorization.

21012221011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35674449.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21012221011 its reverse (11012221012), we get a palindrome (32024442023).

Subtracting from 21012221011 its reverse (11012221012), we obtain a palindrome (9999999999).

The spelling of 21012221011 in words is "twenty-one billion, twelve million, two hundred twenty-one thousand, eleven".