7666991646 has 8 divisors (see below), whose sum is σ = 15333983304. Its totient is φ = 2555663880.

The previous prime is 7666991639. The next prime is 7666991669. The reversal of 7666991646 is 6461996667.

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

7666991646 is an admirable number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 7666991646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 638915965 + ... + 638915976.

It is an arithmetic number, because the mean of its divisors is an integer number (1916747913).

Almost surely, 2^7666991646 is an apocalyptic number.

7666991646 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7666991646 is a wasteful number, since it uses less digits than its factorization.

7666991646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1277831946.

The product of its digits is 17635968, while the sum is 60.

The square root of 7666991646 is about 87561.3593201933. The cubic root of 7666991646 is about 1971.8550938443.

The spelling of 7666991646 in words is "seven billion, six hundred sixty-six million, nine hundred ninety-one thousand, six hundred forty-six".