66554987 has 2 divisors, whose sum is σ = 66554988. Its totient is φ = 66554986.

The previous prime is 66554981. The next prime is 66555023. The reversal of 66554987 is 78945566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66554987 - 2²⁰ = 65506411 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66554981) 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, 33277493 + 33277494.

It is an arithmetic number, because the mean of its divisors is an integer number (33277494).

Almost surely, 2^66554987 is an apocalyptic number.

66554987 is a deficient number, since it is larger than the sum of its proper divisors (1).

66554987 is an equidigital number, since it uses as much as digits as its factorization.

66554987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1814400, while the sum is 50.

The square root of 66554987 is about 8158.1239877805. The cubic root of 66554987 is about 405.2535870577.

The spelling of 66554987 in words is "sixty-six million, five hundred fifty-four thousand, nine hundred eighty-seven".