991006799 has 4 divisors (see below), whose sum is σ = 996735336. Its totient is φ = 985278264.

The previous prime is 991006771. The next prime is 991006813. The reversal of 991006799 is 997600199.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991006799 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 (991006739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2864009 + ... + 2864354.

It is an arithmetic number, because the mean of its divisors is an integer number (249183834).

Almost surely, 2^991006799 is an apocalyptic number.

991006799 is a deficient number, since it is larger than the sum of its proper divisors (5728537).

991006799 is a wasteful number, since it uses less digits than its factorization.

991006799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5728536.

The product of its (nonzero) digits is 275562, while the sum is 50.

The square root of 991006799 is about 31480.2604658856. The cubic root of 991006799 is about 996.9932347571.

The spelling of 991006799 in words is "nine hundred ninety-one million, six thousand, seven hundred ninety-nine".