247417991 has 2 divisors, whose sum is σ = 247417992. Its totient is φ = 247417990.

The previous prime is 247417931. The next prime is 247417993. The reversal of 247417991 is 199714742.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-247417991 is a prime.

It is a super-2 number, since 2×247417991² = 122431324540952162, which contains 22 as substring.

Together with 247417993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247417993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123708995 + 123708996.

It is an arithmetic number, because the mean of its divisors is an integer number (123708996).

Almost surely, 2^247417991 is an apocalyptic number.

247417991 is a deficient number, since it is larger than the sum of its proper divisors (1).

247417991 is an equidigital number, since it uses as much as digits as its factorization.

247417991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127008, while the sum is 44.

The square root of 247417991 is about 15729.5260894917. The cubic root of 247417991 is about 627.7842638349.

The spelling of 247417991 in words is "two hundred forty-seven million, four hundred seventeen thousand, nine hundred ninety-one".