66240439 has 2 divisors, whose sum is σ = 66240440. Its totient is φ = 66240438.

The previous prime is 66240401. The next prime is 66240451. The reversal of 66240439 is 93404266.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66240439 - 2¹⁵ = 66207671 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66240739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33120219 + 33120220.

It is an arithmetic number, because the mean of its divisors is an integer number (33120220).

Almost surely, 2^66240439 is an apocalyptic number.

66240439 is a deficient number, since it is larger than the sum of its proper divisors (1).

66240439 is an equidigital number, since it uses as much as digits as its factorization.

66240439 is an evil number, because the sum of its binary digits is even.

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

The square root of 66240439 is about 8138.8229492968. The cubic root of 66240439 is about 404.6141506245.

The spelling of 66240439 in words is "sixty-six million, two hundred forty thousand, four hundred thirty-nine".