398165951 has 2 divisors, whose sum is σ = 398165952. Its totient is φ = 398165950.

The previous prime is 398165923. The next prime is 398165983. The reversal of 398165951 is 159561893.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 398165951 - 2¹⁴ = 398149567 is a prime.

It is a super-2 number, since 2×398165951² = 317072249071468802, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 398165896 and 398165905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398165851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199082975 + 199082976.

It is an arithmetic number, because the mean of its divisors is an integer number (199082976).

Almost surely, 2^398165951 is an apocalyptic number.

398165951 is a deficient number, since it is larger than the sum of its proper divisors (1).

398165951 is an equidigital number, since it uses as much as digits as its factorization.

398165951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 291600, while the sum is 47.

The square root of 398165951 is about 19954.0960957895. The cubic root of 398165951 is about 735.6784584899.

The spelling of 398165951 in words is "three hundred ninety-eight million, one hundred sixty-five thousand, nine hundred fifty-one".