21520542115 has 8 divisors (see below), whose sum is σ = 25892080128. Its totient is φ = 17171480640.

The previous prime is 21520542103. The next prime is 21520542133. The reversal of 21520542115 is 51124502512.

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

It is not a de Polignac number, because 21520542115 - 2⁵ = 21520542083 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, 5617026 + ... + 5620855.

It is an arithmetic number, because the mean of its divisors is an integer number (3236510016).

Almost surely, 2^21520542115 is an apocalyptic number.

21520542115 is a deficient number, since it is larger than the sum of its proper divisors (4371538013).

21520542115 is a wasteful number, since it uses less digits than its factorization.

21520542115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11238269.

The product of its (nonzero) digits is 4000, while the sum is 28.

The spelling of 21520542115 in words is "twenty-one billion, five hundred twenty million, five hundred forty-two thousand, one hundred fifteen".