6400091 has 2 divisors, whose sum is σ = 6400092. Its totient is φ = 6400090.

The previous prime is 6400033. The next prime is 6400099. The reversal of 6400091 is 1900046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6400091 - 2²² = 2205787 is a prime.

It is a super-2 number, since 2×6400091² = 81922329616562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6400099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200045 + 3200046.

It is an arithmetic number, because the mean of its divisors is an integer number (3200046).

Almost surely, 2^6400091 is an apocalyptic number.

6400091 is a deficient number, since it is larger than the sum of its proper divisors (1).

6400091 is an equidigital number, since it uses as much as digits as its factorization.

6400091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 6400091 is about 2529.8401135250. The cubic root of 6400091 is about 185.6644333082.

The spelling of 6400091 in words is "six million, four hundred thousand, ninety-one".