991709691719 has 8 divisors (see below), whose sum is σ = 993938220288. Its totient is φ = 989481612600.

The previous prime is 991709691691. The next prime is 991709691787. The reversal of 991709691719 is 917196907199.

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

It is a cyclic number.

It is not a de Polignac number, because 991709691719 - 2⁸ = 991709691463 is a prime.

It is a super-2 number, since 2×991709691719² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991709691919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4519394 + ... + 4733744.

It is an arithmetic number, because the mean of its divisors is an integer number (124242277536).

Almost surely, 2^991709691719 is an apocalyptic number.

991709691719 is a deficient number, since it is larger than the sum of its proper divisors (2228528569).

991709691719 is a wasteful number, since it uses less digits than its factorization.

991709691719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224725.

The product of its (nonzero) digits is 17360406, while the sum is 68.

The spelling of 991709691719 in words is "nine hundred ninety-one billion, seven hundred nine million, six hundred ninety-one thousand, seven hundred nineteen".