66697387 has 2 divisors, whose sum is σ = 66697388. Its totient is φ = 66697386.

The previous prime is 66697381. The next prime is 66697403. The reversal of 66697387 is 78379666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66697387 - 2⁷ = 66697259 is a prime.

It is not a weakly prime, because it can be changed into another prime (66697381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33348693 + 33348694.

It is an arithmetic number, because the mean of its divisors is an integer number (33348694).

Almost surely, 2^66697387 is an apocalyptic number.

66697387 is a deficient number, since it is larger than the sum of its proper divisors (1).

66697387 is an equidigital number, since it uses as much as digits as its factorization.

66697387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2286144, while the sum is 52.

The square root of 66697387 is about 8166.8468211422. The cubic root of 66697387 is about 405.5424058982.

The spelling of 66697387 in words is "sixty-six million, six hundred ninety-seven thousand, three hundred eighty-seven".