6400381 has 8 divisors (see below), whose sum is σ = 7298424. Its totient is φ = 5560320.

The previous prime is 6400369. The next prime is 6400391. The reversal of 6400381 is 1830046.

It can be written as a sum of positive squares in 4 ways, for example, as 2160900 + 4239481 = 1470^2 + 2059^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6400381 - 2⁵ = 6400349 is a prime.

It is a super-2 number, since 2×6400381² = 81929753890322, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6400391) 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 7 ways as a sum of consecutive naturals, for example, 14260 + ... + 14701.

It is an arithmetic number, because the mean of its divisors is an integer number (912303).

Almost surely, 2^6400381 is an apocalyptic number.

It is an amenable number.

6400381 is a deficient number, since it is larger than the sum of its proper divisors (898043).

6400381 is a wasteful number, since it uses less digits than its factorization.

6400381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28991.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 6400381 is about 2529.8974287508. The cubic root of 6400381 is about 185.6672375325.

The spelling of 6400381 in words is "six million, four hundred thousand, three hundred eighty-one".