66887491 has 16 divisors (see below), whose sum is σ = 76382208. Its totient is φ = 58017600.

The previous prime is 66887477. The next prime is 66887497. The reversal of 66887491 is 19478866.

It is a cyclic number.

It is not a de Polignac number, because 66887491 - 2⁷ = 66887363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66887497) 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 in 15 ways as a sum of consecutive naturals, for example, 23550 + ... + 26236.

It is an arithmetic number, because the mean of its divisors is an integer number (4773888).

Almost surely, 2^66887491 is an apocalyptic number.

66887491 is a deficient number, since it is larger than the sum of its proper divisors (9494717).

66887491 is a wasteful number, since it uses less digits than its factorization.

66887491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2802.

The product of its digits is 580608, while the sum is 49.

The square root of 66887491 is about 8178.4773032637. The cubic root of 66887491 is about 405.9273390315.

The spelling of 66887491 in words is "sixty-six million, eight hundred eighty-seven thousand, four hundred ninety-one".