999111997 has 4 divisors (see below), whose sum is σ = 1075966780. Its totient is φ = 922257216.

The previous prime is 999111991. The next prime is 999112001. The reversal of 999111997 is 799111999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 799111999 = 7 ⋅114158857.

It can be written as a sum of positive squares in 2 ways, for example, as 80658361 + 918453636 = 8981^2 + 30306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999111997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999111991) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 38427372 + ... + 38427397.

It is an arithmetic number, because the mean of its divisors is an integer number (268991695).

Almost surely, 2^999111997 is an apocalyptic number.

It is an amenable number.

999111997 is a deficient number, since it is larger than the sum of its proper divisors (76854783).

999111997 is a wasteful number, since it uses less digits than its factorization.

999111997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76854782.

The product of its digits is 413343, while the sum is 55.

The square root of 999111997 is about 31608.7329230388. The cubic root of 999111997 is about 999.7039113402.

The spelling of 999111997 in words is "nine hundred ninety-nine million, one hundred eleven thousand, nine hundred ninety-seven".