66785987 has 2 divisors, whose sum is σ = 66785988. Its totient is φ = 66785986.

The previous prime is 66785981. The next prime is 66786017. The reversal of 66785987 is 78958766.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66785987 - 2¹⁴ = 66769603 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66785981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33392993 + 33392994.

It is an arithmetic number, because the mean of its divisors is an integer number (33392994).

Almost surely, 2^66785987 is an apocalyptic number.

66785987 is a deficient number, since it is larger than the sum of its proper divisors (1).

66785987 is an equidigital number, since it uses as much as digits as its factorization.

66785987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 56.

The square root of 66785987 is about 8172.2693910566. The cubic root of 66785987 is about 405.7218989808.

The spelling of 66785987 in words is "sixty-six million, seven hundred eighty-five thousand, nine hundred eighty-seven".