999667 has 2 divisors, whose sum is σ = 999668. Its totient is φ = 999666.

The previous prime is 999653. The next prime is 999671. The reversal of 999667 is 766999.

It is a strong prime.

It is an emirp because it is prime and its reverse (766999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999667 - 2¹⁹ = 475379 is a prime.

It is a super-2 number, since 2×999667² = 1998668221778, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (999067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499833 + 499834.

It is an arithmetic number, because the mean of its divisors is an integer number (499834).

2⁹⁹⁹⁶⁶⁷ is an apocalyptic number.

999667 is a deficient number, since it is larger than the sum of its proper divisors (1).

999667 is an equidigital number, since it uses as much as digits as its factorization.

999667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 46.

The square root of 999667 is about 999.8334861366. The cubic root of 999667 is about 99.9888987677.

The spelling of 999667 in words is "nine hundred ninety-nine thousand, six hundred sixty-seven".