66599397 has 6 divisors (see below), whose sum is σ = 96199142. Its totient is φ = 44399592.

The previous prime is 66599369. The next prime is 66599411. The reversal of 66599397 is 79399566.

It can be written as a sum of positive squares in only one way, i.e., 56160036 + 10439361 = 7494^2 + 3231^2 .

It is not a de Polignac number, because 66599397 - 2⁶ = 66599333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66599317) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3699958 + ... + 3699975.

Almost surely, 2^66599397 is an apocalyptic number.

It is an amenable number.

66599397 is a deficient number, since it is larger than the sum of its proper divisors (29599745).

66599397 is a wasteful number, since it uses less digits than its factorization.

66599397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7399939 (or 7399936 counting only the distinct ones).

The product of its digits is 2755620, while the sum is 54.

The square root of 66599397 is about 8160.8453606229. The cubic root of 66599397 is about 405.3437045735.

The spelling of 66599397 in words is "sixty-six million, five hundred ninety-nine thousand, three hundred ninety-seven".