21520522315 has 4 divisors (see below), whose sum is σ = 25824626784. Its totient is φ = 17216417848.

The previous prime is 21520522313. The next prime is 21520522327. The reversal of 21520522315 is 51322502512.

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

It is a cyclic number.

It is not a de Polignac number, because 21520522315 - 2¹ = 21520522313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21520522313) 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, 2152052227 + ... + 2152052236.

It is an arithmetic number, because the mean of its divisors is an integer number (6456156696).

Almost surely, 2^21520522315 is an apocalyptic number.

21520522315 is a deficient number, since it is larger than the sum of its proper divisors (4304104469).

21520522315 is an equidigital number, since it uses as much as digits as its factorization.

21520522315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4304104468.

The product of its (nonzero) digits is 6000, while the sum is 28.

The spelling of 21520522315 in words is "twenty-one billion, five hundred twenty million, five hundred twenty-two thousand, three hundred fifteen".