6645657947 has 8 divisors (see below), whose sum is σ = 6667710720. Its totient is φ = 6623637480.

The previous prime is 6645657937. The next prime is 6645658051. The reversal of 6645657947 is 7497565466.

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 6645657947 - 2⁶ = 6645657883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6645657917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 445268 + ... + 459950.

It is an arithmetic number, because the mean of its divisors is an integer number (833463840).

Almost surely, 2^6645657947 is an apocalyptic number.

6645657947 is a deficient number, since it is larger than the sum of its proper divisors (22052773).

6645657947 is a wasteful number, since it uses less digits than its factorization.

6645657947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16153.

The product of its digits is 38102400, while the sum is 59.

The square root of 6645657947 is about 81520.9049692163. The cubic root of 6645657947 is about 1880.0929811980.

The spelling of 6645657947 in words is "six billion, six hundred forty-five million, six hundred fifty-seven thousand, nine hundred forty-seven".