6646787909787 has 8 divisors (see below), whose sum is σ = 8872154979136. Its totient is φ = 4426306390152.

The previous prime is 6646787909777. The next prime is 6646787909807. The reversal of 6646787909787 is 7879097876466.

6646787909787 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 6646787909787 - 2¹⁹ = 6646787385499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6646787909777) 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, 1221384253 + ... + 1221389694.

It is an arithmetic number, because the mean of its divisors is an integer number (1109019372392).

Almost surely, 2^{6646787909787} is an apocalyptic number.

6646787909787 is a deficient number, since it is larger than the sum of its proper divisors (2225367069349).

6646787909787 is a wasteful number, since it uses less digits than its factorization.

6646787909787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2442774857.

The product of its (nonzero) digits is 10754021376, while the sum is 84.

The spelling of 6646787909787 in words is "six trillion, six hundred forty-six billion, seven hundred eighty-seven million, nine hundred nine thousand, seven hundred eighty-seven".