21002010221 has 8 divisors (see below), whose sum is σ = 22869703200. Its totient is φ = 19210549680.

The previous prime is 21002010209. The next prime is 21002010229. The reversal of 21002010221 is 12201020012.

It is a happy number.

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 21002010221 - 2⁶ = 21002010157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002010229) 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, 19057535 + ... + 19058636.

It is an arithmetic number, because the mean of its divisors is an integer number (2858712900).

Almost surely, 2^21002010221 is an apocalyptic number.

It is an amenable number.

21002010221 is a deficient number, since it is larger than the sum of its proper divisors (1867692979).

21002010221 is a wasteful number, since it uses less digits than its factorization.

21002010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38116219.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21002010221 its reverse (12201020012), we get a palindrome (33203030233).

The spelling of 21002010221 in words is "twenty-one billion, two million, ten thousand, two hundred twenty-one".