247999 has 2 divisors, whose sum is σ = 248000.
Its totient is φ = 247998.
The previous prime is 247997. The next prime is 248021. The reversal of 247999 is 999742.
It can be divided in two parts, 247 and 999, that multiplied together give a triangular number (246753 = T702).
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 247999 - 21 = 247997 is a prime.
Together with 247997, it forms a pair of twin primes.
247999 is a modest number, since divided by 999 gives 247 as remainder.
It is a plaindrome in base 10.
It is a nialpdrome in base 14.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (247991) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123999 + 124000.
It is an arithmetic number, because the mean of its divisors is an integer number (124000).
2247999 is an apocalyptic number.
247999 is a deficient number, since it is larger than the sum of its proper divisors (1).
247999 is an equidigital number, since it uses as much as digits as its factorization.
247999 is an evil number, because the sum of its binary digits is even.
The product of its digits is 40824, while the sum is 40.
The square root of 247999 is about 497.9949798944.
The cubic root of 247999 is about 62.8275286020.
The spelling of 247999 in words is "two hundred forty-seven thousand, nine hundred ninety-nine".