6438791 has 4 divisors (see below), whose sum is σ = 6481584. Its totient is φ = 6396000.

The previous prime is 6438749. The next prime is 6438799. The reversal of 6438791 is 1978346.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1978346 = 2 ⋅989173.

It is a cyclic number.

It is not a de Polignac number, because 6438791 - 2¹⁴ = 6422407 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 (6438799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21170 + ... + 21471.

It is an arithmetic number, because the mean of its divisors is an integer number (1620396).

Almost surely, 2^6438791 is an apocalyptic number.

6438791 is a deficient number, since it is larger than the sum of its proper divisors (42793).

6438791 is a wasteful number, since it uses less digits than its factorization.

6438791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42792.

The product of its digits is 36288, while the sum is 38.

The square root of 6438791 is about 2537.4772905388. The cubic root of 6438791 is about 186.0379060987.

The spelling of 6438791 in words is "six million, four hundred thirty-eight thousand, seven hundred ninety-one".