21630215245 has 4 divisors (see below), whose sum is σ = 25956258300. Its totient is φ = 17304172192.

The previous prime is 21630215237. The next prime is 21630215267. The reversal of 21630215245 is 54251203612.

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 6024709161 + 15605506084 = 77619^2 + 124922^2 .

It is a cyclic number.

It is not a de Polignac number, because 21630215245 - 2³ = 21630215237 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2163021520 + ... + 2163021529.

It is an arithmetic number, because the mean of its divisors is an integer number (6489064575).

Almost surely, 2^21630215245 is an apocalyptic number.

It is an amenable number.

21630215245 is a deficient number, since it is larger than the sum of its proper divisors (4326043055).

21630215245 is an equidigital number, since it uses as much as digits as its factorization.

21630215245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4326043054.

The product of its (nonzero) digits is 14400, while the sum is 31.

Adding to 21630215245 its reverse (54251203612), we get a palindrome (75881418857).

The spelling of 21630215245 in words is "twenty-one billion, six hundred thirty million, two hundred fifteen thousand, two hundred forty-five".