398216251 has 2 divisors, whose sum is σ = 398216252. Its totient is φ = 398216250.

The previous prime is 398216201. The next prime is 398216261. The reversal of 398216251 is 152612893.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 398216251 - 2¹³ = 398208059 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 398216251.

It is not a weakly prime, because it can be changed into another prime (398216201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199108125 + 199108126.

It is an arithmetic number, because the mean of its divisors is an integer number (199108126).

Almost surely, 2^398216251 is an apocalyptic number.

398216251 is a deficient number, since it is larger than the sum of its proper divisors (1).

398216251 is an equidigital number, since it uses as much as digits as its factorization.

398216251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 37.

The square root of 398216251 is about 19955.3564488335. The cubic root of 398216251 is about 735.7094364178.

The spelling of 398216251 in words is "three hundred ninety-eight million, two hundred sixteen thousand, two hundred fifty-one".