248517991 has 2 divisors, whose sum is σ = 248517992. Its totient is φ = 248517990.

The previous prime is 248517959. The next prime is 248518009. The reversal of 248517991 is 199715842.

248517991 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 a cyclic number.

It is not a de Polignac number, because 248517991 - 2⁵ = 248517959 is a prime.

It is a super-2 number, since 2×248517991² = 123522383701352162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (248517491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124258995 + 124258996.

It is an arithmetic number, because the mean of its divisors is an integer number (124258996).

Almost surely, 2^248517991 is an apocalyptic number.

248517991 is a deficient number, since it is larger than the sum of its proper divisors (1).

248517991 is an equidigital number, since it uses as much as digits as its factorization.

248517991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 46.

The square root of 248517991 is about 15764.4533999755. The cubic root of 248517991 is about 628.7132474990.

The spelling of 248517991 in words is "two hundred forty-eight million, five hundred seventeen thousand, nine hundred ninety-one".