991493 has 2 divisors, whose sum is σ = 991494. Its totient is φ = 991492.

The previous prime is 991483. The next prime is 991499. The reversal of 991493 is 394199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 925444 + 66049 = 962^2 + 257^2 .

It is a cyclic number.

It is not a de Polignac number, because 991493 - 2⁶ = 991429 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495746 + 495747.

It is an arithmetic number, because the mean of its divisors is an integer number (495747).

2⁹⁹¹⁴⁹³ is an apocalyptic number.

It is an amenable number.

991493 is a deficient number, since it is larger than the sum of its proper divisors (1).

991493 is an equidigital number, since it uses as much as digits as its factorization.

991493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8748, while the sum is 35.

The square root of 991493 is about 995.7374151853. The cubic root of 991493 is about 99.7156254108.

The spelling of 991493 in words is "nine hundred ninety-one thousand, four hundred ninety-three".