8640397 has 4 divisors (see below), whose sum is σ = 8688316. Its totient is φ = 8592480.

The previous prime is 8640391. The next prime is 8640407. The reversal of 8640397 is 7930468.

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

It can be written as a sum of positive squares in 2 ways, for example, as 236196 + 8404201 = 486^2 + 2899^2 .

It is a cyclic number.

It is not a de Polignac number, because 8640397 - 2¹¹ = 8638349 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 (8640391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23688 + ... + 24049.

It is an arithmetic number, because the mean of its divisors is an integer number (2172079).

Almost surely, 2^8640397 is an apocalyptic number.

It is an amenable number.

8640397 is a deficient number, since it is larger than the sum of its proper divisors (47919).

8640397 is a wasteful number, since it uses less digits than its factorization.

8640397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47918.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 8640397 is about 2939.4552216355. The cubic root of 8640397 is about 205.2002564255.

The spelling of 8640397 in words is "eight million, six hundred forty thousand, three hundred ninety-seven".