6391043137 has 4 divisors (see below), whose sum is σ = 6399442116. Its totient is φ = 6382644160.

The previous prime is 6391043119. The next prime is 6391043147. The reversal of 6391043137 is 7313401936.

It is a Cunningham number, because it is equal to 79944²+1.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16777216 + 6374265921 = 4096^2 + 79839^2 .

It is a cyclic number.

It is not a de Polignac number, because 6391043137 - 2²³ = 6382654529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6391043096 and 6391043105.

It is not an unprimeable number, because it can be changed into a prime (6391043147) 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, 4198348 + ... + 4199869.

It is an arithmetic number, because the mean of its divisors is an integer number (1599860529).

Almost surely, 2^6391043137 is an apocalyptic number.

It is an amenable number.

6391043137 is a deficient number, since it is larger than the sum of its proper divisors (8398979).

6391043137 is an equidigital number, since it uses as much as digits as its factorization.

6391043137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8398978.

The product of its (nonzero) digits is 40824, while the sum is 37.

The square root of 6391043137 is about 79944.0000062544. Note that the first 5 decimals coincide. The cubic root of 6391043137 is about 1855.7690025113.

The spelling of 6391043137 in words is "six billion, three hundred ninety-one million, forty-three thousand, one hundred thirty-seven".