1991006695 has 16 divisors (see below), whose sum is σ = 2406942720. Its totient is φ = 1581008544.

The previous prime is 1991006659. The next prime is 1991006711. The reversal of 1991006695 is 5966001991.

It is a cyclic number.

It is not a de Polignac number, because 1991006695 - 2⁹ = 1991006183 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1269802 + ... + 1271368.

It is an arithmetic number, because the mean of its divisors is an integer number (150433920).

Almost surely, 2^1991006695 is an apocalyptic number.

1991006695 is a deficient number, since it is larger than the sum of its proper divisors (415936025).

1991006695 is a wasteful number, since it uses less digits than its factorization.

1991006695 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3294.

The product of its (nonzero) digits is 131220, while the sum is 46.

The square root of 1991006695 is about 44620.6980559471. The cubic root of 1991006695 is about 1258.0297364831.

The spelling of 1991006695 in words is "one billion, nine hundred ninety-one million, six thousand, six hundred ninety-five".