6540399 has 16 divisors (see below), whose sum is σ = 10024800. Its totient is φ = 4209408.

The previous prime is 6540383. The next prime is 6540407. The reversal of 6540399 is 9930456.

It is not a de Polignac number, because 6540399 - 2⁴ = 6540383 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6540329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3394 + ... + 4959.

It is an arithmetic number, because the mean of its divisors is an integer number (626550).

Almost surely, 2^6540399 is an apocalyptic number.

6540399 is a deficient number, since it is larger than the sum of its proper divisors (3484401).

6540399 is a wasteful number, since it uses less digits than its factorization.

6540399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8391 (or 8385 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 6540399 is about 2557.4203799923. The cubic root of 6540399 is about 187.0113998789.

The spelling of 6540399 in words is "six million, five hundred forty thousand, three hundred ninety-nine".