21705520339 has 8 divisors (see below), whose sum is σ = 21986100000. Its totient is φ = 21425756352.

The previous prime is 21705520313. The next prime is 21705520357. The reversal of 21705520339 is 93302550712.

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

It is a cyclic number.

It is not a de Polignac number, because 21705520339 - 2⁷ = 21705520211 is a prime.

It is a super-2 number, since 2×21705520339² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21705520298 and 21705520307.

It is not an unprimeable number, because it can be changed into a prime (21705524339) 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, 150264 + ... + 256885.

It is an arithmetic number, because the mean of its divisors is an integer number (2748262500).

Almost surely, 2^21705520339 is an apocalyptic number.

21705520339 is a deficient number, since it is larger than the sum of its proper divisors (280579661).

21705520339 is an equidigital number, since it uses as much as digits as its factorization.

21705520339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407837.

The product of its (nonzero) digits is 56700, while the sum is 37.

The spelling of 21705520339 in words is "twenty-one billion, seven hundred five million, five hundred twenty thousand, three hundred thirty-nine".