21705520359 has 16 divisors (see below), whose sum is σ = 29048180480. Its totient is φ = 14416704000.

The previous prime is 21705520357. The next prime is 21705520451. The reversal of 21705520359 is 95302550712.

It is not a de Polignac number, because 21705520359 - 2¹ = 21705520357 is a prime.

It is a super-2 number, since 2×21705520359² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21705520357) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 892359 + ... + 916359.

It is an arithmetic number, because the mean of its divisors is an integer number (1815511280).

Almost surely, 2^21705520359 is an apocalyptic number.

21705520359 is a deficient number, since it is larger than the sum of its proper divisors (7342660121).

21705520359 is a wasteful number, since it uses less digits than its factorization.

21705520359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25110.

The product of its (nonzero) digits is 94500, while the sum is 39.

The spelling of 21705520359 in words is "twenty-one billion, seven hundred five million, five hundred twenty thousand, three hundred fifty-nine".