163996256509 has 8 divisors (see below), whose sum is σ = 168457606200. Its totient is φ = 159536434176.

The previous prime is 163996256503. The next prime is 163996256539. The reversal of 163996256509 is 905652699361.

It can be written as a sum of positive squares in 4 ways, for example, as 4013856025 + 159982400484 = 63355^2 + 399978^2 .

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 163996256509 - 2⁵ = 163996256477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163996256503) 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, 162484 + ... + 595309.

It is an arithmetic number, because the mean of its divisors is an integer number (21057200775).

Almost surely, 2^163996256509 is an apocalyptic number.

It is an amenable number.

163996256509 is a deficient number, since it is larger than the sum of its proper divisors (4461349691).

163996256509 is an equidigital number, since it uses as much as digits as its factorization.

163996256509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 763679.

The product of its (nonzero) digits is 23619600, while the sum is 61.

The spelling of 163996256509 in words is "one hundred sixty-three billion, nine hundred ninety-six million, two hundred fifty-six thousand, five hundred nine".