8400389 has 4 divisors (see below), whose sum is σ = 8406240. Its totient is φ = 8394540.

The previous prime is 8400377. The next prime is 8400409. The reversal of 8400389 is 9830048.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 8400389 - 2⁴ = 8400373 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8400319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 872 + ... + 4190.

It is an arithmetic number, because the mean of its divisors is an integer number (2101560).

Almost surely, 2^8400389 is an apocalyptic number.

It is an amenable number.

8400389 is a deficient number, since it is larger than the sum of its proper divisors (5851).

8400389 is a wasteful number, since it uses less digits than its factorization.

8400389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5850.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 8400389 is about 2898.3424573366. The cubic root of 8400389 is about 203.2824092366.

The spelling of 8400389 in words is "eight million, four hundred thousand, three hundred eighty-nine".