66968399 has 2 divisors, whose sum is σ = 66968400. Its totient is φ = 66968398.

The previous prime is 66968381. The next prime is 66968413. The reversal of 66968399 is 99386966.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66968399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66968359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33484199 + 33484200.

It is an arithmetic number, because the mean of its divisors is an integer number (33484200).

Almost surely, 2^66968399 is an apocalyptic number.

66968399 is a deficient number, since it is larger than the sum of its proper divisors (1).

66968399 is an equidigital number, since it uses as much as digits as its factorization.

66968399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3779136, while the sum is 56.

The square root of 66968399 is about 8183.4222058989. The cubic root of 66968399 is about 406.0909447880.

The spelling of 66968399 in words is "sixty-six million, nine hundred sixty-eight thousand, three hundred ninety-nine".