1991763210608 has 20 divisors (see below), whose sum is σ = 3931853320728. Its totient is φ = 977091385920.

The previous prime is 1991763210599. The next prime is 1991763210611. The reversal of 1991763210608 is 8060123671991.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a self number, because there is not a number n which added to its sum of digits gives 1991763210608.

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, 1174387838 + ... + 1174389533.

Almost surely, 2^{1991763210608} is an apocalyptic number.

It is an amenable number.

1991763210608 is a deficient number, since it is larger than the sum of its proper divisors (1940090110120).

1991763210608 is a wasteful number, since it uses less digits than its factorization.

1991763210608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2348777432 (or 2348777426 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 53.

The spelling of 1991763210608 in words is "one trillion, nine hundred ninety-one billion, seven hundred sixty-three million, two hundred ten thousand, six hundred eight".