66831 has 4 divisors (see below), whose sum is σ = 89112. Its totient is φ = 44552.

The previous prime is 66821. The next prime is 66841. The reversal of 66831 is 13866.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (66821) and next prime (66841).

It is a cyclic number.

It is not a de Polignac number, because 66831 - 2¹¹ = 64783 is a prime.

It is a super-2 number, since 2×66831² = 8932765122, which contains 22 as substring.

It is a D-number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11136 + ... + 11141.

It is an arithmetic number, because the mean of its divisors is an integer number (22278).

2⁶⁶⁸³¹ is an apocalyptic number.

66831 is the 164-th centered pentagonal number.

66831 is a deficient number, since it is larger than the sum of its proper divisors (22281).

66831 is a wasteful number, since it uses less digits than its factorization.

66831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22280.

The product of its digits is 864, while the sum is 24.

The square root of 66831 is about 258.5169240108. The cubic root of 66831 is about 40.5813029168.

The spelling of 66831 in words is "sixty-six thousand, eight hundred thirty-one".