163004561 has 4 divisors (see below), whose sum is σ = 166980324. Its totient is φ = 159028800.

The previous prime is 163004539. The next prime is 163004587. The reversal of 163004561 is 165400361.

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 88078225 + 74926336 = 9385^2 + 8656^2 .

It is a cyclic number.

It is not a de Polignac number, because 163004561 - 2¹⁸ = 162742417 is a prime.

It is a super-3 number, since 3×163004561³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 163004561.

It is not an unprimeable number, because it can be changed into a prime (163004531) 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, 1987820 + ... + 1987901.

It is an arithmetic number, because the mean of its divisors is an integer number (41745081).

Almost surely, 2^163004561 is an apocalyptic number.

It is an amenable number.

163004561 is a deficient number, since it is larger than the sum of its proper divisors (3975763).

163004561 is an equidigital number, since it uses as much as digits as its factorization.

163004561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3975762.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 163004561 is about 12767.3239560998. The cubic root of 163004561 is about 546.2606521146.

The spelling of 163004561 in words is "one hundred sixty-three million, four thousand, five hundred sixty-one".