6631603778 has 18 divisors (see below), whose sum is σ = 10076003481. Its totient is φ = 3273478384.

The previous prime is 6631603679. The next prime is 6631603813. The reversal of 6631603778 is 8773061366.

It can be written as a sum of positive squares in 2 ways, for example, as 5927922049 + 703681729 = 76993^2 + 26527^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=57583.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10249451 + ... + 10250097.

Almost surely, 2^6631603778 is an apocalyptic number.

6631603778 is a deficient number, since it is larger than the sum of its proper divisors (3444399703).

6631603778 is an frugal number, since it uses more digits than its factorization.

6631603778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1474 (or 738 counting only the distinct ones).

The product of its (nonzero) digits is 762048, while the sum is 47.

The square root of 6631603778 is about 81434.6595621299. The cubic root of 6631603778 is about 1878.7667120719.

The spelling of 6631603778 in words is "six billion, six hundred thirty-one million, six hundred three thousand, seven hundred seventy-eight".