999491 has 2 divisors, whose sum is σ = 999492. Its totient is φ = 999490.

The previous prime is 999451. The next prime is 999499. The reversal of 999491 is 194999.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999491 is a prime.

It is a super-3 number, since 3×999491³ = 2995421331333383313, which contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (999499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499745 + 499746.

It is an arithmetic number, because the mean of its divisors is an integer number (499746).

2⁹⁹⁹⁴⁹¹ is an apocalyptic number.

999491 is a deficient number, since it is larger than the sum of its proper divisors (1).

999491 is an equidigital number, since it uses as much as digits as its factorization.

999491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26244, while the sum is 41.

The square root of 999491 is about 999.7454676066. The cubic root of 999491 is about 99.9830304538.

The spelling of 999491 in words is "nine hundred ninety-nine thousand, four hundred ninety-one".