161365563 has 12 divisors (see below), whose sum is σ = 234293800. Its totient is φ = 107018496.

The previous prime is 161365543. The next prime is 161365583. The reversal of 161365563 is 365563161.

161365563 is a `hidden beast` number, since 1 + 61 + 36 + 5 + 563 = 666.

It is an interprime number because it is at equal distance from previous prime (161365543) and next prime (161365583).

It is not a de Polignac number, because 161365563 - 2⁸ = 161365307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161365543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44713 + ... + 48186.

Almost surely, 2^161365563 is an apocalyptic number.

161365563 is a deficient number, since it is larger than the sum of its proper divisors (72928237).

161365563 is a wasteful number, since it uses less digits than its factorization.

161365563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93098 (or 93095 counting only the distinct ones).

The product of its digits is 48600, while the sum is 36.

The square root of 161365563 is about 12702.9745729101. The cubic root of 161365563 is about 544.4236119368.

It can be divided in two parts, 1613 and 65563, that added together give a palindrome (67176).

The spelling of 161365563 in words is "one hundred sixty-one million, three hundred sixty-five thousand, five hundred sixty-three".