6640400455 has 8 divisors (see below), whose sum is σ = 8581440672. Its totient is φ = 4903680288.

The previous prime is 6640400453. The next prime is 6640400479. The reversal of 6640400455 is 5540040466.

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

It is not a de Polignac number, because 6640400455 - 2¹ = 6640400453 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6640400455.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640400453) 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 7 ways as a sum of consecutive naturals, for example, 51079939 + ... + 51080068.

It is an arithmetic number, because the mean of its divisors is an integer number (1072680084).

Almost surely, 2^6640400455 is an apocalyptic number.

6640400455 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

6640400455 is a deficient number, since it is larger than the sum of its proper divisors (1941040217).

6640400455 is a wasteful number, since it uses less digits than its factorization.

6640400455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102160025.

The product of its (nonzero) digits is 57600, while the sum is 34.

The square root of 6640400455 is about 81488.6523081588. The cubic root of 6640400455 is about 1879.5970593168.

The spelling of 6640400455 in words is "six billion, six hundred forty million, four hundred thousand, four hundred fifty-five".