163971638 has 4 divisors (see below), whose sum is σ = 245957460. Its totient is φ = 81985818.

The previous prime is 163971629. The next prime is 163971641. The reversal of 163971638 is 836179361.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 40992908 + ... + 40992911.

It is an arithmetic number, because the mean of its divisors is an integer number (61489365).

Almost surely, 2^163971638 is an apocalyptic number.

163971638 is a deficient number, since it is larger than the sum of its proper divisors (81985822).

163971638 is an equidigital number, since it uses as much as digits as its factorization.

163971638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81985821.

The product of its digits is 163296, while the sum is 44.

The square root of 163971638 is about 12805.1410769269. The cubic root of 163971638 is about 547.3388117616.

The spelling of 163971638 in words is "one hundred sixty-three million, nine hundred seventy-one thousand, six hundred thirty-eight".