6640266651 has 4 divisors (see below), whose sum is σ = 8853688872. Its totient is φ = 4426844432.

The previous prime is 6640266649. The next prime is 6640266653. The reversal of 6640266651 is 1566620466.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (6640266649) and next prime (6640266653).

It is a cyclic number.

It is not a de Polignac number, because 6640266651 - 2¹ = 6640266649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6640266653) 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 3 ways as a sum of consecutive naturals, for example, 1106711106 + ... + 1106711111.

It is an arithmetic number, because the mean of its divisors is an integer number (2213422218).

Almost surely, 2^6640266651 is an apocalyptic number.

6640266651 is a deficient number, since it is larger than the sum of its proper divisors (2213422221).

6640266651 is a wasteful number, since it uses less digits than its factorization.

6640266651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2213422220.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 6640266651 is about 81487.8313062754. The cubic root of 6640266651 is about 1879.5844346117.

The spelling of 6640266651 in words is "six billion, six hundred forty million, two hundred sixty-six thousand, six hundred fifty-one".