247018991 has 2 divisors, whose sum is σ = 247018992. Its totient is φ = 247018990.

The previous prime is 247018987. The next prime is 247018997. The reversal of 247018991 is 199810742.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 247018991 - 2² = 247018987 is a prime.

It is a super-2 number, since 2×247018991² = 122036763829316162, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247018997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123509495 + 123509496.

It is an arithmetic number, because the mean of its divisors is an integer number (123509496).

Almost surely, 2^247018991 is an apocalyptic number.

247018991 is a deficient number, since it is larger than the sum of its proper divisors (1).

247018991 is an equidigital number, since it uses as much as digits as its factorization.

247018991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 247018991 is about 15716.8378180854. The cubic root of 247018991 is about 627.4466156709.

The spelling of 247018991 in words is "two hundred forty-seven million, eighteen thousand, nine hundred ninety-one".