66666487 has 2 divisors, whose sum is σ = 66666488. Its totient is φ = 66666486.

The previous prime is 66666437. The next prime is 66666493. The reversal of 66666487 is 78466666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66666487 - 2⁷ = 66666359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66666487.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66666427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333243 + 33333244.

It is an arithmetic number, because the mean of its divisors is an integer number (33333244).

Almost surely, 2^66666487 is an apocalyptic number.

66666487 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666487 is an equidigital number, since it uses as much as digits as its factorization.

66666487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 49.

The square root of 66666487 is about 8164.9548069784. The cubic root of 66666487 is about 405.4797687816.

The spelling of 66666487 in words is "sixty-six million, six hundred sixty-six thousand, four hundred eighty-seven".