66339257 has 4 divisors (see below), whose sum is σ = 66458916. Its totient is φ = 66219600.

The previous prime is 66339233. The next prime is 66339281. The reversal of 66339257 is 75293366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75293366 = 2 ⋅37646683.

It is an interprime number because it is at equal distance from previous prime (66339233) and next prime (66339281).

It can be written as a sum of positive squares in 2 ways, for example, as 23580736 + 42758521 = 4856^2 + 6539^2 .

It is a cyclic number.

It is not a de Polignac number, because 66339257 - 2⁶ = 66339193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66339227) 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, 58994 + ... + 60107.

It is an arithmetic number, because the mean of its divisors is an integer number (16614729).

Almost surely, 2^66339257 is an apocalyptic number.

It is an amenable number.

66339257 is a deficient number, since it is larger than the sum of its proper divisors (119659).

66339257 is a wasteful number, since it uses less digits than its factorization.

66339257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119658.

The product of its digits is 204120, while the sum is 41.

The square root of 66339257 is about 8144.8914664347. The cubic root of 66339257 is about 404.8152528304.

The spelling of 66339257 in words is "sixty-six million, three hundred thirty-nine thousand, two hundred fifty-seven".