163644538 has 16 divisors (see below), whose sum is σ = 249694056. Its totient is φ = 80421120.

The previous prime is 163644463. The next prime is 163644539. The reversal of 163644538 is 835446361.

It can be written as a sum of positive squares in 4 ways, for example, as 127848249 + 35796289 = 11307^2 + 5983^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 163644538.

It is not an unprimeable number, because it can be changed into a prime (163644539) 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 7 ways as a sum of consecutive naturals, for example, 43908 + ... + 47488.

Almost surely, 2^163644538 is an apocalyptic number.

163644538 is a deficient number, since it is larger than the sum of its proper divisors (86049518).

163644538 is a wasteful number, since it uses less digits than its factorization.

163644538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3969.

The product of its digits is 207360, while the sum is 40.

The square root of 163644538 is about 12792.3624870467. The cubic root of 163644538 is about 546.9746152272.

It can be divided in two parts, 16364 and 4538, that added together give a palindrome (20902).

The spelling of 163644538 in words is "one hundred sixty-three million, six hundred forty-four thousand, five hundred thirty-eight".