8390665 has 4 divisors (see below), whose sum is σ = 10068804. Its totient is φ = 6712528.

The previous prime is 8390663. The next prime is 8390671. The reversal of 8390665 is 5660938.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5660938 = 2 ⋅2830469.

It can be written as a sum of positive squares in 2 ways, for example, as 1149184 + 7241481 = 1072^2 + 2691^2 .

It is a cyclic number.

It is not a de Polignac number, because 8390665 - 2¹ = 8390663 is a prime.

It is a Duffinian number.

8390665 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8390663) 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, 839062 + ... + 839071.

It is an arithmetic number, because the mean of its divisors is an integer number (2517201).

Almost surely, 2^8390665 is an apocalyptic number.

It is an amenable number.

8390665 is a deficient number, since it is larger than the sum of its proper divisors (1678139).

8390665 is a wasteful number, since it uses less digits than its factorization.

8390665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678138.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 8390665 is about 2896.6644610655. The cubic root of 8390665 is about 203.2039413877.

The spelling of 8390665 in words is "eight million, three hundred ninety thousand, six hundred sixty-five".