163164633721 has 4 divisors (see below), whose sum is σ = 165839463844. Its totient is φ = 160489803600.

The previous prime is 163164633703. The next prime is 163164633767. The reversal of 163164633721 is 127336461361.

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 54633920121 + 108530713600 = 233739^2 + 329440^2 .

It is a cyclic number.

It is not a de Polignac number, because 163164633721 - 2⁵ = 163164633689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163164633701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1337414970 + ... + 1337415091.

It is an arithmetic number, because the mean of its divisors is an integer number (41459865961).

Almost surely, 2^163164633721 is an apocalyptic number.

It is an amenable number.

163164633721 is a deficient number, since it is larger than the sum of its proper divisors (2674830123).

163164633721 is an equidigital number, since it uses as much as digits as its factorization.

163164633721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2674830122.

The product of its digits is 326592, while the sum is 43.

The spelling of 163164633721 in words is "one hundred sixty-three billion, one hundred sixty-four million, six hundred thirty-three thousand, seven hundred twenty-one".