6663691835978 has 16 divisors (see below), whose sum is σ = 10130267877120. Its totient is φ = 3287234282976.

The previous prime is 6663691835971. The next prime is 6663691836001. The reversal of 6663691835978 is 8795381963666.

It is a junction number, because it is equal to n+sod(n) for n = 6663691835899 and 6663691835908.

It is not an unprimeable number, because it can be changed into a prime (6663691835971) 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, 74556698 + ... + 74646021.

It is an arithmetic number, because the mean of its divisors is an integer number (633141742320).

Almost surely, 2^{6663691835978} is an apocalyptic number.

6663691835978 is a deficient number, since it is larger than the sum of its proper divisors (3466576041142).

6663691835978 is a wasteful number, since it uses less digits than its factorization.

6663691835978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149203021.

The product of its digits is 2116316160, while the sum is 77.

The spelling of 6663691835978 in words is "six trillion, six hundred sixty-three billion, six hundred ninety-one million, eight hundred thirty-five thousand, nine hundred seventy-eight".