66317638 has 16 divisors (see below), whose sum is σ = 105894000. Its totient is φ = 31059072.

The previous prime is 66317633. The next prime is 66317651. The reversal of 66317638 is 83671366.

It is a self number, because there is not a number n which added to its sum of digits gives 66317638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66317633) 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 in 7 ways as a sum of consecutive naturals, for example, 6423 + ... + 13186.

It is an arithmetic number, because the mean of its divisors is an integer number (6618375).

Almost surely, 2^66317638 is an apocalyptic number.

66317638 is a deficient number, since it is larger than the sum of its proper divisors (39576362).

66317638 is a wasteful number, since it uses less digits than its factorization.

66317638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19719.

The product of its digits is 108864, while the sum is 40.

The square root of 66317638 is about 8143.5642073972. The cubic root of 66317638 is about 404.7712735829.

The spelling of 66317638 in words is "sixty-six million, three hundred seventeen thousand, six hundred thirty-eight".