6445399 has 4 divisors (see below), whose sum is σ = 6595336. Its totient is φ = 6295464.

The previous prime is 6445393. The next prime is 6445403. The reversal of 6445399 is 9935446.

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 6445399 - 2³ = 6445391 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 (6445391) 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, 74904 + ... + 74989.

It is an arithmetic number, because the mean of its divisors is an integer number (1648834).

Almost surely, 2^6445399 is an apocalyptic number.

6445399 is a deficient number, since it is larger than the sum of its proper divisors (149937).

6445399 is a wasteful number, since it uses less digits than its factorization.

6445399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149936.

The product of its digits is 116640, while the sum is 40.

The square root of 6445399 is about 2538.7790372539. The cubic root of 6445399 is about 186.1015266435.

The spelling of 6445399 in words is "six million, four hundred forty-five thousand, three hundred ninety-nine".