21310130221 has 4 divisors (see below), whose sum is σ = 21312292444. Its totient is φ = 21307968000.

The previous prime is 21310130183. The next prime is 21310130239. The reversal of 21310130221 is 12203101312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20731968196 + 578162025 = 143986^2 + 24045^2 .

It is a cyclic number.

It is not a de Polignac number, because 21310130221 - 2¹¹ = 21310128173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21310130195 and 21310130204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310130251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1066260 + ... + 1086061.

It is an arithmetic number, because the mean of its divisors is an integer number (5328073111).

Almost surely, 2^21310130221 is an apocalyptic number.

It is an amenable number.

21310130221 is a deficient number, since it is larger than the sum of its proper divisors (2162223).

21310130221 is an equidigital number, since it uses as much as digits as its factorization.

21310130221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2162222.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21310130221 its reverse (12203101312), we get a palindrome (33513231533).

The spelling of 21310130221 in words is "twenty-one billion, three hundred ten million, one hundred thirty thousand, two hundred twenty-one".