163665561601 has 16 divisors (see below), whose sum is σ = 165484747008. Its totient is φ = 161858233600.

The previous prime is 163665561589. The next prime is 163665561617. The reversal of 163665561601 is 106165566361.

It is a cyclic number.

It is not a de Polignac number, because 163665561601 - 2⁵ = 163665561569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163665561691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35709156 + ... + 35713738.

It is an arithmetic number, because the mean of its divisors is an integer number (10342796688).

Almost surely, 2^163665561601 is an apocalyptic number.

It is an amenable number.

163665561601 is a deficient number, since it is larger than the sum of its proper divisors (1819185407).

163665561601 is a wasteful number, since it uses less digits than its factorization.

163665561601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5792.

The product of its (nonzero) digits is 583200, while the sum is 46.

The spelling of 163665561601 in words is "one hundred sixty-three billion, six hundred sixty-five million, five hundred sixty-one thousand, six hundred one".