8991487 has 4 divisors (see below), whose sum is σ = 9520416. Its totient is φ = 8462560.

The previous prime is 8991449. The next prime is 8991517. The reversal of 8991487 is 7841998.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8991487 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 (8994487) 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, 264439 + ... + 264472.

It is an arithmetic number, because the mean of its divisors is an integer number (2380104).

Almost surely, 2^8991487 is an apocalyptic number.

8991487 is a deficient number, since it is larger than the sum of its proper divisors (528929).

8991487 is a wasteful number, since it uses less digits than its factorization.

8991487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528928.

The product of its digits is 145152, while the sum is 46.

The square root of 8991487 is about 2998.5808309932. The cubic root of 8991487 is about 207.9427773433.

The spelling of 8991487 in words is "eight million, nine hundred ninety-one thousand, four hundred eighty-seven".