21002201221 has 8 divisors (see below), whose sum is σ = 21537316800. Its totient is φ = 20473733280.

The previous prime is 21002201179. The next prime is 21002201249. The reversal of 21002201221 is 12210220012.

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 21002201221 - 2¹¹ = 21002199173 is a prime.

It is a super-2 number, since 2×21002201221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002201261) 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, 1655511 + ... + 1668148.

It is an arithmetic number, because the mean of its divisors is an integer number (2692164600).

Almost surely, 2^21002201221 is an apocalyptic number.

It is an amenable number.

21002201221 is a deficient number, since it is larger than the sum of its proper divisors (535115579).

21002201221 is an equidigital number, since it uses as much as digits as its factorization.

21002201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3323819.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21002201221 its reverse (12210220012), we get a palindrome (33212421233).

The spelling of 21002201221 in words is "twenty-one billion, two million, two hundred one thousand, two hundred twenty-one".