66431 has 2 divisors, whose sum is σ = 66432.
Its totient is φ = 66430.
The previous prime is 66413. The next prime is 66449. The reversal of 66431 is 13466.
Adding to 66431 its reverse (13466), we get a palindrome (79897).
Together with previous prime (66413) it forms an Ormiston pair, because they use the same digits, order apart.
It is a balanced prime because it is at equal distance from previous prime (66413) and next prime (66449).
It is a cyclic number.
It is not a de Polignac number, because 66431 - 210 = 65407 is a prime.
It is a super-2 number, since 2×664312 = 8826155522, which contains 22 as substring.
It is a Sophie Germain prime.
It is a Chen prime.
It is a pancake number, because a pancake can be divided into 66431 parts by 364 straight cuts.
It is a plaindrome in base 9.
It is a nialpdrome in base 10.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (66491) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33215 + 33216.
It is an arithmetic number, because the mean of its divisors is an integer number (33216).
266431 is an apocalyptic number.
66431 is a deficient number, since it is larger than the sum of its proper divisors (1).
66431 is an equidigital number, since it uses as much as digits as its factorization.
66431 is an evil number, because the sum of its binary digits is even.
The product of its digits is 432, while the sum is 20.
The square root of 66431 is about 257.7421191812.
The cubic root of 66431 is about 40.5001778176.
The spelling of 66431 in words is "sixty-six thousand, four hundred thirty-one".