66385399 has 2 divisors, whose sum is σ = 66385400. Its totient is φ = 66385398.

The previous prime is 66385369. The next prime is 66385433. The reversal of 66385399 is 99358366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66385399 - 2⁷ = 66385271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66385369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33192699 + 33192700.

It is an arithmetic number, because the mean of its divisors is an integer number (33192700).

Almost surely, 2^66385399 is an apocalyptic number.

66385399 is a deficient number, since it is larger than the sum of its proper divisors (1).

66385399 is an equidigital number, since it uses as much as digits as its factorization.

66385399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1049760, while the sum is 49.

The square root of 66385399 is about 8147.7235471020. The cubic root of 66385399 is about 404.9090869452.

The spelling of 66385399 in words is "sixty-six million, three hundred eighty-five thousand, three hundred ninety-nine".