66887857 has 2 divisors, whose sum is σ = 66887858. Its totient is φ = 66887856.

The previous prime is 66887839. The next prime is 66887867. The reversal of 66887857 is 75878866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38489616 + 28398241 = 6204^2 + 5329^2 .

It is a cyclic number.

It is not a de Polignac number, because 66887857 - 2⁷ = 66887729 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66887798 and 66887807.

It is not a weakly prime, because it can be changed into another prime (66887827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33443928 + 33443929.

It is an arithmetic number, because the mean of its divisors is an integer number (33443929).

Almost surely, 2^66887857 is an apocalyptic number.

It is an amenable number.

66887857 is a deficient number, since it is larger than the sum of its proper divisors (1).

66887857 is an equidigital number, since it uses as much as digits as its factorization.

66887857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4515840, while the sum is 55.

The square root of 66887857 is about 8178.4996790365. The cubic root of 66887857 is about 405.9280794248.

The spelling of 66887857 in words is "sixty-six million, eight hundred eighty-seven thousand, eight hundred fifty-seven".