66640367 has 4 divisors (see below), whose sum is σ = 68441496. Its totient is φ = 64839240.

The previous prime is 66640363. The next prime is 66640369. The reversal of 66640367 is 76304666.

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

It is a cyclic number.

It is not a de Polignac number, because 66640367 - 2² = 66640363 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66640367.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66640363) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 900509 + ... + 900582.

It is an arithmetic number, because the mean of its divisors is an integer number (17110374).

Almost surely, 2^66640367 is an apocalyptic number.

66640367 is a deficient number, since it is larger than the sum of its proper divisors (1801129).

66640367 is a wasteful number, since it uses less digits than its factorization.

66640367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801128.

The product of its (nonzero) digits is 108864, while the sum is 38.

The square root of 66640367 is about 8163.3551313170. The cubic root of 66640367 is about 405.4268060635.

The spelling of 66640367 in words is "sixty-six million, six hundred forty thousand, three hundred sixty-seven".