21002223021 has 48 divisors (see below), whose sum is σ = 32004152640. Its totient is φ = 12211430400.

The previous prime is 21002223019. The next prime is 21002223031. The reversal of 21002223021 is 12032220012.

It is a happy number.

It is not a de Polignac number, because 21002223021 - 2¹ = 21002223019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002223031) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3860115 + ... + 3865551.

It is an arithmetic number, because the mean of its divisors is an integer number (666753180).

Almost surely, 2^21002223021 is an apocalyptic number.

It is an amenable number.

21002223021 is a deficient number, since it is larger than the sum of its proper divisors (11001929619).

21002223021 is a wasteful number, since it uses less digits than its factorization.

21002223021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5886 (or 5873 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21002223021 its reverse (12032220012), we get a palindrome (33034443033).

The spelling of 21002223021 in words is "twenty-one billion, two million, two hundred twenty-three thousand, twenty-one".