21520434513 has 8 divisors (see below), whose sum is σ = 28838104000. Its totient is φ = 14274860688.

The previous prime is 21520434497. The next prime is 21520434547. The reversal of 21520434513 is 31543402512.

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

It is not a de Polignac number, because 21520434513 - 2⁴ = 21520434497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21520434563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18023218 + ... + 18024411.

It is an arithmetic number, because the mean of its divisors is an integer number (3604763000).

Almost surely, 2^21520434513 is an apocalyptic number.

It is an amenable number.

21520434513 is a deficient number, since it is larger than the sum of its proper divisors (7317669487).

21520434513 is a wasteful number, since it uses less digits than its factorization.

21520434513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36047831.

The product of its (nonzero) digits is 14400, while the sum is 30.

The spelling of 21520434513 in words is "twenty-one billion, five hundred twenty million, four hundred thirty-four thousand, five hundred thirteen".