398163121 has 4 divisors (see below), whose sum is σ = 398228544. Its totient is φ = 398097700.

The previous prime is 398163113. The next prime is 398163131. The reversal of 398163121 is 121361893.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 398163121 - 2³ = 398163113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398163131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22525 + ... + 36106.

It is an arithmetic number, because the mean of its divisors is an integer number (99557136).

Almost surely, 2^398163121 is an apocalyptic number.

It is an amenable number.

398163121 is a deficient number, since it is larger than the sum of its proper divisors (65423).

398163121 is an equidigital number, since it uses as much as digits as its factorization.

398163121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65422.

The product of its digits is 7776, while the sum is 34.

The square root of 398163121 is about 19954.0251829048. The cubic root of 398163121 is about 735.6767155190.

The spelling of 398163121 in words is "three hundred ninety-eight million, one hundred sixty-three thousand, one hundred twenty-one".