21201110021 has 16 divisors (see below), whose sum is σ = 26268816000. Its totient is φ = 16661913408.

The previous prime is 21201109961. The next prime is 21201110027. The reversal of 21201110021 is 12001110212.

It is not a de Polignac number, because 21201110021 - 2³⁰ = 20127368197 is a prime.

It is a super-2 number, since 2×21201110021² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21201109984 and 21201110011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201110027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 768251 + ... + 795368.

It is an arithmetic number, because the mean of its divisors is an integer number (1641801000).

Almost surely, 2^21201110021 is an apocalyptic number.

It is an amenable number.

21201110021 is a deficient number, since it is larger than the sum of its proper divisors (5067705979).

21201110021 is a wasteful number, since it uses less digits than its factorization.

21201110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1563788.

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

Adding to 21201110021 its reverse (12001110212), we get a palindrome (33202220233).

The spelling of 21201110021 in words is "twenty-one billion, two hundred one million, one hundred ten thousand, twenty-one".