20017687136769 has 81 divisors (see below), whose sum is σ = 33807327533577. Its totient is φ = 11380425412608.

The previous prime is 20017687136747. The next prime is 20017687136809. The reversal of 20017687136769 is 96763178671002.

The square root of 20017687136769 is 4474113.

It is a perfect power (a square), and thus also a powerful number.

20017687136769 is a `hidden beast` number, since 20 + 0 + 176 + 87 + 1 + 367 + 6 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 9032519322225 + 10985167814544 = 3005415^2 + 3314388^2 .

It is not a de Polignac number, because 20017687136769 - 2⁷ = 20017687136641 is a prime.

It is a super-2 number, since 2×20017687136769² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (20017687136569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 24146787447 + ... + 24146788275.

Almost surely, 2^{20017687136769} is an apocalyptic number.

20017687136769 is the 4474113-rd square number.

20017687136769 is the 2237057-th centered octagonal number.

It is an amenable number.

20017687136769 is a deficient number, since it is larger than the sum of its proper divisors (13789640396808).

20017687136769 is an frugal number, since it uses more digits than its factorization.

20017687136769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2192 (or 1096 counting only the distinct ones).

The product of its (nonzero) digits is 32006016, while the sum is 63.

The spelling of 20017687136769 in words is "twenty trillion, seventeen billion, six hundred eighty-seven million, one hundred thirty-six thousand, seven hundred sixty-nine".