66375418 has 4 divisors (see below), whose sum is σ = 99563130. Its totient is φ = 33187708.

The previous prime is 66375391. The next prime is 66375427. The reversal of 66375418 is 81457366.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81457366 = 2 ⋅40728683.

It can be written as a sum of positive squares in only one way, i.e., 63728289 + 2647129 = 7983^2 + 1627^2 .

It is a super-2 number, since 2×66375418² = 8811392229349448, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16593853 + ... + 16593856.

Almost surely, 2^66375418 is an apocalyptic number.

66375418 is a deficient number, since it is larger than the sum of its proper divisors (33187712).

66375418 is a wasteful number, since it uses less digits than its factorization.

66375418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33187711.

The product of its digits is 120960, while the sum is 40.

The square root of 66375418 is about 8147.1110217058. Note that the first 3 decimals coincide. The cubic root of 66375418 is about 404.8887933253. Note that the first 3 decimals are identical.

The spelling of 66375418 in words is "sixty-six million, three hundred seventy-five thousand, four hundred eighteen".