16640938 has 4 divisors (see below), whose sum is σ = 24961410. Its totient is φ = 8320468.

The previous prime is 16640933. The next prime is 16640951. The reversal of 16640938 is 83904661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83904661 = 89 ⋅942749.

It can be written as a sum of positive squares in only one way, i.e., 15896169 + 744769 = 3987^2 + 863^2 .

It is a junction number, because it is equal to n+sod(n) for n = 16640897 and 16640906.

It is not an unprimeable number, because it can be changed into a prime (16640933) 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 as a sum of consecutive naturals, namely, 4160233 + ... + 4160236.

Almost surely, 2^16640938 is an apocalyptic number.

16640938 is a deficient number, since it is larger than the sum of its proper divisors (8320472).

16640938 is an equidigital number, since it uses as much as digits as its factorization.

16640938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8320471.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 16640938 is about 4079.3305823382. The cubic root of 16640938 is about 255.3049689709.

It can be divided in two parts, 16640 and 938, that added together give a triangular number (17578 = T₁₈₇).

The spelling of 16640938 in words is "sixteen million, six hundred forty thousand, nine hundred thirty-eight".