391256249 has 2 divisors, whose sum is σ = 391256250. Its totient is φ = 391256248.

The previous prime is 391256237. The next prime is 391256267. The reversal of 391256249 is 942652193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 340033600 + 51222649 = 18440^2 + 7157^2 .

It is a cyclic number.

It is not a de Polignac number, because 391256249 - 2⁸ = 391255993 is a prime.

It is not a weakly prime, because it can be changed into another prime (391256279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195628124 + 195628125.

It is an arithmetic number, because the mean of its divisors is an integer number (195628125).

Almost surely, 2^391256249 is an apocalyptic number.

It is an amenable number.

391256249 is a deficient number, since it is larger than the sum of its proper divisors (1).

391256249 is an equidigital number, since it uses as much as digits as its factorization.

391256249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 41.

The square root of 391256249 is about 19780.1984064872. The cubic root of 391256249 is about 731.3979897329.

The spelling of 391256249 in words is "three hundred ninety-one million, two hundred fifty-six thousand, two hundred forty-nine".