391948489 has 2 divisors, whose sum is σ = 391948490. Its totient is φ = 391948488.

The previous prime is 391948477. The next prime is 391948507. The reversal of 391948489 is 984849193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 354945600 + 37002889 = 18840^2 + 6083^2 .

It is a cyclic number.

It is not a de Polignac number, because 391948489 - 2¹⁷ = 391817417 is a prime.

It is not a weakly prime, because it can be changed into another prime (391948439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195974244 + 195974245.

It is an arithmetic number, because the mean of its divisors is an integer number (195974245).

Almost surely, 2^391948489 is an apocalyptic number.

It is an amenable number.

391948489 is a deficient number, since it is larger than the sum of its proper divisors (1).

391948489 is an equidigital number, since it uses as much as digits as its factorization.

391948489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2239488, while the sum is 55.

The square root of 391948489 is about 19797.6889812927. The cubic root of 391948489 is about 731.8290837132.

The spelling of 391948489 in words is "three hundred ninety-one million, nine hundred forty-eight thousand, four hundred eighty-nine".