6660660646 has 4 divisors (see below), whose sum is σ = 9990990972. Its totient is φ = 3330330322.

The previous prime is 6660660623. The next prime is 6660660659. The reversal of 6660660646 is 6460660666.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 6660660596 and 6660660605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1665165160 + ... + 1665165163.

It is an arithmetic number, because the mean of its divisors is an integer number (2497747743).

Almost surely, 2^6660660646 is an apocalyptic number.

6660660646 is a deficient number, since it is larger than the sum of its proper divisors (3330330326).

6660660646 is a wasteful number, since it uses less digits than its factorization.

6660660646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3330330325.

The product of its (nonzero) digits is 1119744, while the sum is 46.

The square root of 6660660646 is about 81612.8705903671. The cubic root of 6660660646 is about 1881.5066997667.

The spelling of 6660660646 in words is "six billion, six hundred sixty million, six hundred sixty thousand, six hundred forty-six".