6400243 has 4 divisors (see below), whose sum is σ = 6418728. Its totient is φ = 6381760.

The previous prime is 6400241. The next prime is 6400253. The reversal of 6400243 is 3420046.

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

It is a cyclic number.

It is not a de Polignac number, because 6400243 - 2¹ = 6400241 is a prime.

It is a super-2 number, since 2×6400243² = 81926220918098, which contains 22 as substring.

It is a Duffinian number.

6400243 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6400243.

It is not an unprimeable number, because it can be changed into a prime (6400241) 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, 8713 + ... + 9418.

It is an arithmetic number, because the mean of its divisors is an integer number (1604682).

Almost surely, 2^6400243 is an apocalyptic number.

6400243 is a deficient number, since it is larger than the sum of its proper divisors (18485).

6400243 is a wasteful number, since it uses less digits than its factorization.

6400243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18484.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 6400243 is about 2529.8701547708. The cubic root of 6400243 is about 185.6659031191.

Adding to 6400243 its reverse (3420046), we get a palindrome (9820289).

The spelling of 6400243 in words is "six million, four hundred thousand, two hundred forty-three".