999623 has 2 divisors, whose sum is σ = 999624.
Its totient is φ = 999622.
The previous prime is 999613. The next prime is 999631. The reversal of 999623 is 326999.
Subtracting from 999623 its product of digits (26244), we obtain a palindrome (973379).
999623 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a strong prime.
It is an emirp because it is prime and its reverse (326999) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 999623 - 214 = 983239 is a prime.
It is a super-2 number, since 2×9996232 = 1998492284258, which contains 22 as substring.
It is a Sophie Germain prime.
It is a congruent number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 999623.
It is not a weakly prime, because it can be changed into another prime (999613) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499811 + 499812.
It is an arithmetic number, because the mean of its divisors is an integer number (499812).
2999623 is an apocalyptic number.
999623 is a deficient number, since it is larger than the sum of its proper divisors (1).
999623 is an equidigital number, since it uses as much as digits as its factorization.
999623 is an evil number, because the sum of its binary digits is even.
The product of its digits is 26244, while the sum is 38.
The square root of 999623 is about 999.8114822305.
The cubic root of 999623 is about 99.9874317538.
The spelling of 999623 in words is "nine hundred ninety-nine thousand, six hundred twenty-three".