398508779 has 2 divisors, whose sum is σ = 398508780. Its totient is φ = 398508778.

The previous prime is 398508769. The next prime is 398508797. The reversal of 398508779 is 977805893.

Together with next prime (398508797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 398508779 - 2⁴ = 398508763 is a prime.

It is not a weakly prime, because it can be changed into another prime (398508709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199254389 + 199254390.

It is an arithmetic number, because the mean of its divisors is an integer number (199254390).

Almost surely, 2^398508779 is an apocalyptic number.

398508779 is a deficient number, since it is larger than the sum of its proper divisors (1).

398508779 is an equidigital number, since it uses as much as digits as its factorization.

398508779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3810240, while the sum is 56.

The square root of 398508779 is about 19962.6846641427. The cubic root of 398508779 is about 735.8895420196.

The spelling of 398508779 in words is "three hundred ninety-eight million, five hundred eight thousand, seven hundred seventy-nine".