66938797 has 2 divisors, whose sum is σ = 66938798. Its totient is φ = 66938796.

The previous prime is 66938771. The next prime is 66938801. The reversal of 66938797 is 79783966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54449641 + 12489156 = 7379^2 + 3534^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66938797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66938747) 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, 33469398 + 33469399.

It is an arithmetic number, because the mean of its divisors is an integer number (33469399).

Almost surely, 2^66938797 is an apocalyptic number.

It is an amenable number.

66938797 is a deficient number, since it is larger than the sum of its proper divisors (1).

66938797 is an equidigital number, since it uses as much as digits as its factorization.

66938797 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3429216, while the sum is 55.

The square root of 66938797 is about 8181.6133494562. The cubic root of 66938797 is about 406.0311012599.

The spelling of 66938797 in words is "sixty-six million, nine hundred thirty-eight thousand, seven hundred ninety-seven".