8864721 has 10 divisors (see below), whose sum is σ = 13242482. Its totient is φ = 5909760.

The previous prime is 8864663. The next prime is 8864731. The reversal of 8864721 is 1274688.

8864721 is a `hidden beast` number, since 8 + 8 + 647 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 8346321 + 518400 = 2889^2 + 720^2 .

It is not a de Polignac number, because 8864721 - 2¹⁰ = 8863697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8864731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 54640 + ... + 54801.

Almost surely, 2^8864721 is an apocalyptic number.

8864721 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

8864721 is a deficient number, since it is larger than the sum of its proper divisors (4377761).

8864721 is a wasteful number, since it uses less digits than its factorization.

8864721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109453 (or 109444 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 8864721 is about 2977.3681331001. The cubic root of 8864721 is about 206.9609252016.

The spelling of 8864721 in words is "eight million, eight hundred sixty-four thousand, seven hundred twenty-one".