398278949 has 2 divisors, whose sum is σ = 398278950. Its totient is φ = 398278948.

The previous prime is 398278939. The next prime is 398278967. The reversal of 398278949 is 949872893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 381616225 + 16662724 = 19535^2 + 4082^2 .

It is an emirp because it is prime and its reverse (949872893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398278949 - 2²⁴ = 381501733 is a prime.

It is a super-2 number, since 2×398278949² = 317252242433089202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398278919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199139474 + 199139475.

It is an arithmetic number, because the mean of its divisors is an integer number (199139475).

Almost surely, 2^398278949 is an apocalyptic number.

It is an amenable number.

398278949 is a deficient number, since it is larger than the sum of its proper divisors (1).

398278949 is an equidigital number, since it uses as much as digits as its factorization.

398278949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 59.

The square root of 398278949 is about 19956.9273436569. The cubic root of 398278949 is about 735.7480461677.

The spelling of 398278949 in words is "three hundred ninety-eight million, two hundred seventy-eight thousand, nine hundred forty-nine".