21705205517022 has 16 divisors (see below), whose sum is σ = 45695169509760. Its totient is φ = 6854275426392.

The previous prime is 21705205516961. The next prime is 21705205517029. The reversal of 21705205517022 is 22071550250712.

It is a super-2 number, since 2×21705205517022² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21705205517029) 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 7 ways as a sum of consecutive naturals, for example, 95198269698 + ... + 95198269925.

It is an arithmetic number, because the mean of its divisors is an integer number (2855948094360).

Almost surely, 2^{21705205517022} is an apocalyptic number.

21705205517022 is an abundant number, since it is smaller than the sum of its proper divisors (23989963992738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21705205517022 is a wasteful number, since it uses less digits than its factorization.

21705205517022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190396539647.

The product of its (nonzero) digits is 98000, while the sum is 39.

Adding to 21705205517022 its reverse (22071550250712), we get a palindrome (43776755767734).

The spelling of 21705205517022 in words is "twenty-one trillion, seven hundred five billion, two hundred five million, five hundred seventeen thousand, twenty-two".