6659453978 has 8 divisors (see below), whose sum is σ = 10056222900. Its totient is φ = 3307379680.

The previous prime is 6659453953. The next prime is 6659454019. The reversal of 6659453978 is 8793549566.

It can be written as a sum of positive squares in 2 ways, for example, as 6657417649 + 2036329 = 81593^2 + 1427^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 6659453978.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 11173283 + ... + 11173878.

Almost surely, 2^6659453978 is an apocalyptic number.

6659453978 is a deficient number, since it is larger than the sum of its proper divisors (3396768922).

6659453978 is a wasteful number, since it uses less digits than its factorization.

6659453978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22347312.

The product of its digits is 48988800, while the sum is 62.

The square root of 6659453978 is about 81605.4776225224. The cubic root of 6659453978 is about 1881.3930728478.

The spelling of 6659453978 in words is "six billion, six hundred fifty-nine million, four hundred fifty-three thousand, nine hundred seventy-eight".