163810561 has 4 divisors (see below), whose sum is σ = 166117824. Its totient is φ = 161503300.

The previous prime is 163810547. The next prime is 163810579. The reversal of 163810561 is 165018361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 163810561 - 2²⁷ = 29592833 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163811561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1153525 + ... + 1153666.

It is an arithmetic number, because the mean of its divisors is an integer number (41529456).

Almost surely, 2^163810561 is an apocalyptic number.

It is an amenable number.

163810561 is a deficient number, since it is larger than the sum of its proper divisors (2307263).

163810561 is an equidigital number, since it uses as much as digits as its factorization.

163810561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2307262.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 163810561 is about 12798.8499874012. The cubic root of 163810561 is about 547.1595275477.

The spelling of 163810561 in words is "one hundred sixty-three million, eight hundred ten thousand, five hundred sixty-one".