398165641 has 2 divisors, whose sum is σ = 398165642. Its totient is φ = 398165640.

The previous prime is 398165629. The next prime is 398165671. The reversal of 398165641 is 146561893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201044041 + 197121600 = 14179^2 + 14040^2 .

It is a cyclic number.

It is not a de Polignac number, because 398165641 - 2¹⁹ = 397641353 is a prime.

It is not a weakly prime, because it can be changed into another prime (398165671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199082820 + 199082821.

It is an arithmetic number, because the mean of its divisors is an integer number (199082821).

Almost surely, 2^398165641 is an apocalyptic number.

It is an amenable number.

398165641 is a deficient number, since it is larger than the sum of its proper divisors (1).

398165641 is an equidigital number, since it uses as much as digits as its factorization.

398165641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 43.

The square root of 398165641 is about 19954.0883279593. The cubic root of 398165641 is about 735.6782675642.

The spelling of 398165641 in words is "three hundred ninety-eight million, one hundred sixty-five thousand, six hundred forty-one".