6663494978 has 64 divisors (see below), whose sum is σ = 12259952640. Its totient is φ = 2653005312.

The previous prime is 6663494963. The next prime is 6663494993. The reversal of 6663494978 is 8794943666.

It is an interprime number because it is at equal distance from previous prime (6663494963) and next prime (6663494993).

It is a self number, because there is not a number n which added to its sum of digits gives 6663494978.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2930450 + ... + 2932722.

It is an arithmetic number, because the mean of its divisors is an integer number (191561760).

Almost surely, 2^6663494978 is an apocalyptic number.

6663494978 is a deficient number, since it is larger than the sum of its proper divisors (5596457662).

6663494978 is a wasteful number, since it uses less digits than its factorization.

6663494978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2511.

The product of its digits is 47029248, while the sum is 62.

The square root of 6663494978 is about 81630.2332349969. The cubic root of 6663494978 is about 1881.7735430865.

The spelling of 6663494978 in words is "six billion, six hundred sixty-three million, four hundred ninety-four thousand, nine hundred seventy-eight".