6640405401 has 16 divisors (see below), whose sum is σ = 10119880064. Its totient is φ = 3794079744.

The previous prime is 6640405381. The next prime is 6640405441. The reversal of 6640405401 is 1045040466.

6640405401 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6640405401 - 2⁷ = 6640405273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6640405441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 287001 + ... + 309273.

It is an arithmetic number, because the mean of its divisors is an integer number (632492504).

Almost surely, 2^6640405401 is an apocalyptic number.

It is an amenable number.

6640405401 is a deficient number, since it is larger than the sum of its proper divisors (3479474663).

6640405401 is a wasteful number, since it uses less digits than its factorization.

6640405401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36480.

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 6640405401 is about 81488.6826559370. The cubic root of 6640405401 is about 1879.5975259797.

Adding to 6640405401 its reverse (1045040466), we get a palindrome (7685445867).

The spelling of 6640405401 in words is "six billion, six hundred forty million, four hundred five thousand, four hundred one".