6640400051 has 8 divisors (see below), whose sum is σ = 6775961904. Its totient is φ = 6505218720.

The previous prime is 6640400047. The next prime is 6640400059. The reversal of 6640400051 is 1500040466.

It is a happy number.

6640400051 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 6640400051 - 2² = 6640400047 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640400059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59741 + ... + 129806.

It is an arithmetic number, because the mean of its divisors is an integer number (846995238).

Almost surely, 2^6640400051 is an apocalyptic number.

6640400051 is a deficient number, since it is larger than the sum of its proper divisors (135561853).

6640400051 is a wasteful number, since it uses less digits than its factorization.

6640400051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190261.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 6640400051 is about 81488.6498292860. The cubic root of 6640400051 is about 1879.5970211988.

The spelling of 6640400051 in words is "six billion, six hundred forty million, four hundred thousand, fifty-one".