16131638 has 4 divisors (see below), whose sum is σ = 24197460. Its totient is φ = 8065818.

The previous prime is 16131637. The next prime is 16131653. The reversal of 16131638 is 83613161.

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

It is a self number, because there is not a number n which added to its sum of digits gives 16131638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16131637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4032908 + ... + 4032911.

It is an arithmetic number, because the mean of its divisors is an integer number (6049365).

Almost surely, 2^16131638 is an apocalyptic number.

16131638 is a deficient number, since it is larger than the sum of its proper divisors (8065822).

16131638 is an equidigital number, since it uses as much as digits as its factorization.

16131638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8065821.

The product of its digits is 2592, while the sum is 29.

The square root of 16131638 is about 4016.4210436656. The cubic root of 16131638 is about 252.6733795979.

Adding to 16131638 its reverse (83613161), we get a palindrome (99744799).

The spelling of 16131638 in words is "sixteen million, one hundred thirty-one thousand, six hundred thirty-eight".