21605217002315 has 8 divisors (see below), whose sum is σ = 26238624986448. Its totient is φ = 17075930546080.

The previous prime is 21605217002293. The next prime is 21605217002321. The reversal of 21605217002315 is 51320071250612.

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

It is not a de Polignac number, because 21605217002315 - 2³² = 21600922035019 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26030381516 + ... + 26030382345.

It is an arithmetic number, because the mean of its divisors is an integer number (3279828123306).

Almost surely, 2^{21605217002315} is an apocalyptic number.

21605217002315 is a deficient number, since it is larger than the sum of its proper divisors (4633407984133).

21605217002315 is an equidigital number, since it uses as much as digits as its factorization.

21605217002315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52060763949.

The product of its (nonzero) digits is 25200, while the sum is 35.

Adding to 21605217002315 its reverse (51320071250612), we get a palindrome (72925288252927).

The spelling of 21605217002315 in words is "twenty-one trillion, six hundred five billion, two hundred seventeen million, two thousand, three hundred fifteen".