16640438 has 4 divisors (see below), whose sum is σ = 24960660. Its totient is φ = 8320218.

The previous prime is 16640413. The next prime is 16640453. The reversal of 16640438 is 83404661.

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 (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4160108 + ... + 4160111.

It is an arithmetic number, because the mean of its divisors is an integer number (6240165).

Almost surely, 2^16640438 is an apocalyptic number.

16640438 is a deficient number, since it is larger than the sum of its proper divisors (8320222).

16640438 is an equidigital number, since it uses as much as digits as its factorization.

16640438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8320221.

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 16640438 is about 4079.2692973129. The cubic root of 16640438 is about 255.3024119483.

It can be divided in two parts, 166 and 40438, that added together give a palindrome (40604).

The spelling of 16640438 in words is "sixteen million, six hundred forty thousand, four hundred thirty-eight".