21242404265 has 8 divisors (see below), whose sum is σ = 25494178248. Its totient is φ = 16991728000.

The previous prime is 21242404259. The next prime is 21242404273. The reversal of 21242404265 is 56240424212.

It can be written as a sum of positive squares in 4 ways, for example, as 1050278464 + 20192125801 = 32408^2 + 142099^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21242404265 - 2¹⁰ = 21242403241 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 231236 + ... + 309765.

It is an arithmetic number, because the mean of its divisors is an integer number (3186772281).

Almost surely, 2^21242404265 is an apocalyptic number.

It is an amenable number.

21242404265 is a deficient number, since it is larger than the sum of its proper divisors (4251773983).

21242404265 is an equidigital number, since it uses as much as digits as its factorization.

21242404265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548859.

The product of its (nonzero) digits is 30720, while the sum is 32.

Adding to 21242404265 its reverse (56240424212), we get a palindrome (77482828477).

The spelling of 21242404265 in words is "twenty-one billion, two hundred forty-two million, four hundred four thousand, two hundred sixty-five".