66939 has 8 divisors (see below), whose sum is σ = 91152. Its totient is φ = 43680.

The previous prime is 66931. The next prime is 66943. The reversal of 66939 is 93966.

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

It is not a de Polignac number, because 66939 - 2³ = 66931 is a prime.

It is a d-powerful number, because it can be written as 6 + 6⁵ + 9² + 3³ + 9⁵ .

66939 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (66931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52 + ... + 369.

It is an arithmetic number, because the mean of its divisors is an integer number (11394).

2⁶⁶⁹³⁹ is an apocalyptic number.

66939 is a deficient number, since it is larger than the sum of its proper divisors (24213).

66939 is a wasteful number, since it uses less digits than its factorization.

66939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477.

The product of its digits is 8748, while the sum is 33.

The square root of 66939 is about 258.7257234988. The cubic root of 66939 is about 40.6031511706.

The spelling of 66939 in words is "sixty-six thousand, nine hundred thirty-nine".