66518438 has 32 divisors (see below), whose sum is σ = 119798784. Its totient is φ = 27083232.

The previous prime is 66518423. The next prime is 66518443. The reversal of 66518438 is 83481566.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 66518395 and 66518404.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53156 + ... + 54392.

It is an arithmetic number, because the mean of its divisors is an integer number (3743712).

Almost surely, 2^66518438 is an apocalyptic number.

66518438 is a deficient number, since it is larger than the sum of its proper divisors (53280346).

66518438 is a wasteful number, since it uses less digits than its factorization.

66518438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1436.

The product of its digits is 138240, while the sum is 41.

The square root of 66518438 is about 8155.8836431131. The cubic root of 66518438 is about 405.1793911377.

The spelling of 66518438 in words is "sixty-six million, five hundred eighteen thousand, four hundred thirty-eight".