6400398791 has 2 divisors, whose sum is σ = 6400398792. Its totient is φ = 6400398790.

The previous prime is 6400398779. The next prime is 6400398817. The reversal of 6400398791 is 1978930046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6400398791 - 2⁶ = 6400398727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6400398701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200199395 + 3200199396.

It is an arithmetic number, because the mean of its divisors is an integer number (3200199396).

Almost surely, 2^6400398791 is an apocalyptic number.

6400398791 is a deficient number, since it is larger than the sum of its proper divisors (1).

6400398791 is an equidigital number, since it uses as much as digits as its factorization.

6400398791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 326592, while the sum is 47.

The square root of 6400398791 is about 80002.4924049245. The cubic root of 6400398791 is about 1856.6740956411.

The spelling of 6400398791 in words is "six billion, four hundred million, three hundred ninety-eight thousand, seven hundred ninety-one".