66787487 has 4 divisors (see below), whose sum is σ = 71925000. Its totient is φ = 61649976.

The previous prime is 66787477. The next prime is 66787541. The reversal of 66787487 is 78478766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66787487 - 2²⁴ = 50010271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66787447) 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 3 ways as a sum of consecutive naturals, for example, 2568737 + ... + 2568762.

It is an arithmetic number, because the mean of its divisors is an integer number (17981250).

Almost surely, 2^66787487 is an apocalyptic number.

66787487 is a deficient number, since it is larger than the sum of its proper divisors (5137513).

66787487 is a wasteful number, since it uses less digits than its factorization.

66787487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5137512.

The product of its digits is 3161088, while the sum is 53.

The square root of 66787487 is about 8172.3611643148. The cubic root of 66787487 is about 405.7249364358.

The spelling of 66787487 in words is "sixty-six million, seven hundred eighty-seven thousand, four hundred eighty-seven".