5666399 has 4 divisors (see below), whose sum is σ = 5719464. Its totient is φ = 5613336.

The previous prime is 5666393. The next prime is 5666407. The reversal of 5666399 is 9936665.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9936665 = 5 ⋅1987333.

It is a cyclic number.

It is not a de Polignac number, because 5666399 - 2⁴ = 5666383 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 (5666393) 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, 26372 + ... + 26585.

It is an arithmetic number, because the mean of its divisors is an integer number (1429866).

Almost surely, 2^5666399 is an apocalyptic number.

5666399 is a deficient number, since it is larger than the sum of its proper divisors (53065).

5666399 is a wasteful number, since it uses less digits than its factorization.

5666399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53064.

The product of its digits is 262440, while the sum is 44.

The square root of 5666399 is about 2380.4199209383. The cubic root of 5666399 is about 178.2799009184.

The spelling of 5666399 in words is "five million, six hundred sixty-six thousand, three hundred ninety-nine".