66398439 has 16 divisors (see below), whose sum is σ = 90529920. Its totient is φ = 43275360.

The previous prime is 66398399. The next prime is 66398443. The reversal of 66398439 is 93489366.

It is not a de Polignac number, because 66398439 - 2¹¹ = 66396391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66398459) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31744 + ... + 33770.

It is an arithmetic number, because the mean of its divisors is an integer number (5658120).

Almost surely, 2^66398439 is an apocalyptic number.

66398439 is a deficient number, since it is larger than the sum of its proper divisors (24131481).

66398439 is a wasteful number, since it uses less digits than its factorization.

66398439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2270.

The product of its digits is 839808, while the sum is 48.

The square root of 66398439 is about 8148.5237313270. The cubic root of 66398439 is about 404.9355971362.

The spelling of 66398439 in words is "sixty-six million, three hundred ninety-eight thousand, four hundred thirty-nine".