66187489 has 4 divisors (see below), whose sum is σ = 67801860. Its totient is φ = 64573120.

The previous prime is 66187463. The next prime is 66187519. The reversal of 66187489 is 98478166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98478166 = 2 ⋅49239083.

It can be written as a sum of positive squares in 2 ways, for example, as 25928464 + 40259025 = 5092^2 + 6345^2 .

It is a cyclic number.

It is not a de Polignac number, because 66187489 - 2⁹ = 66186977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66187189) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807124 + ... + 807205.

It is an arithmetic number, because the mean of its divisors is an integer number (16950465).

Almost surely, 2^66187489 is an apocalyptic number.

It is an amenable number.

66187489 is a deficient number, since it is larger than the sum of its proper divisors (1614371).

66187489 is a wasteful number, since it uses less digits than its factorization.

66187489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614370.

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

The square root of 66187489 is about 8135.5693715929. The cubic root of 66187489 is about 404.5063110091.

The spelling of 66187489 in words is "sixty-six million, one hundred eighty-seven thousand, four hundred eighty-nine".