999993791 has 2 divisors, whose sum is σ = 999993792. Its totient is φ = 999993790.

The previous prime is 999993763. The next prime is 999993811. The reversal of 999993791 is 197399999.

It is a strong prime.

It is an emirp because it is prime and its reverse (197399999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999993791 - 2²² = 995799487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999993721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499996895 + 499996896.

It is an arithmetic number, because the mean of its divisors is an integer number (499996896).

Almost surely, 2^999993791 is an apocalyptic number.

999993791 is a deficient number, since it is larger than the sum of its proper divisors (1).

999993791 is an equidigital number, since it uses as much as digits as its factorization.

999993791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11160261, while the sum is 65.

The square root of 999993791 is about 31622.6784286214. The cubic root of 999993791 is about 999.9979303290.

The spelling of 999993791 in words is "nine hundred ninety-nine million, nine hundred ninety-three thousand, seven hundred ninety-one".