163687661765 has 4 divisors (see below), whose sum is σ = 196425194124. Its totient is φ = 130950129408.

The previous prime is 163687661737. The next prime is 163687661773. The reversal of 163687661765 is 567166786361.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 65782503361 + 97905158404 = 256481^2 + 312898^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-163687661765 is a prime.

It is a super-2 number, since 2×163687661765² (a number of 23 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 = 163687661698 and 163687661707.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16368766172 + ... + 16368766181.

It is an arithmetic number, because the mean of its divisors is an integer number (49106298531).

Almost surely, 2^163687661765 is an apocalyptic number.

It is an amenable number.

163687661765 is a deficient number, since it is larger than the sum of its proper divisors (32737532359).

163687661765 is an equidigital number, since it uses as much as digits as its factorization.

163687661765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32737532358.

The product of its digits is 45722880, while the sum is 62.

The spelling of 163687661765 in words is "one hundred sixty-three billion, six hundred eighty-seven million, six hundred sixty-one thousand, seven hundred sixty-five".