66407638 has 8 divisors (see below), whose sum is σ = 108667080. Its totient is φ = 30185280.

The previous prime is 66407629. The next prime is 66407639. The reversal of 66407638 is 83670466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66407638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66407639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1509243 + ... + 1509286.

It is an arithmetic number, because the mean of its divisors is an integer number (13583385).

Almost surely, 2^66407638 is an apocalyptic number.

66407638 is a deficient number, since it is larger than the sum of its proper divisors (42259442).

66407638 is a wasteful number, since it uses less digits than its factorization.

66407638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3018542.

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 66407638 is about 8149.0881698507. The cubic root of 66407638 is about 404.9542965243.

It can be divided in two parts, 66 and 407638, that added together give a palindrome (407704).

The spelling of 66407638 in words is "sixty-six million, four hundred seven thousand, six hundred thirty-eight".