66338431 has 2 divisors, whose sum is σ = 66338432. Its totient is φ = 66338430.

The previous prime is 66338413. The next prime is 66338473. The reversal of 66338431 is 13483366.

Together with previous prime (66338413) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66338431 - 2¹³ = 66330239 is a prime.

It is a super-2 number, since 2×66338431² = 8801574855083522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66338401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33169215 + 33169216.

It is an arithmetic number, because the mean of its divisors is an integer number (33169216).

Almost surely, 2^66338431 is an apocalyptic number.

66338431 is a deficient number, since it is larger than the sum of its proper divisors (1).

66338431 is an equidigital number, since it uses as much as digits as its factorization.

66338431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 34.

The square root of 66338431 is about 8144.8407596466. The cubic root of 66338431 is about 404.8135726850.

The spelling of 66338431 in words is "sixty-six million, three hundred thirty-eight thousand, four hundred thirty-one".