6391493938 has 4 divisors (see below), whose sum is σ = 9587240910. Its totient is φ = 3195746968.

The previous prime is 6391493887. The next prime is 6391493959. The reversal of 6391493938 is 8393941936.

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

It can be written as a sum of positive squares in only one way, i.e., 6382891449 + 8602489 = 79893^2 + 2933^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1597873483 + ... + 1597873486.

Almost surely, 2^6391493938 is an apocalyptic number.

6391493938 is a deficient number, since it is larger than the sum of its proper divisors (3195746972).

6391493938 is a wasteful number, since it uses less digits than its factorization.

6391493938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3195746971.

The product of its digits is 3779136, while the sum is 55.

The square root of 6391493938 is about 79946.8194364229. The cubic root of 6391493938 is about 1855.8126345567.

The spelling of 6391493938 in words is "six billion, three hundred ninety-one million, four hundred ninety-three thousand, nine hundred thirty-eight".