398549521 has 4 divisors (see below), whose sum is σ = 401224500. Its totient is φ = 395874544.

The previous prime is 398549509. The next prime is 398549537. The reversal of 398549521 is 125945893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125945893 = 673 ⋅187141.

It can be written as a sum of positive squares in 2 ways, for example, as 36180225 + 362369296 = 6015^2 + 19036^2 .

It is a cyclic number.

It is not a de Polignac number, because 398549521 - 2⁹ = 398549009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398549621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1337266 + ... + 1337563.

It is an arithmetic number, because the mean of its divisors is an integer number (100306125).

Almost surely, 2^398549521 is an apocalyptic number.

It is an amenable number.

398549521 is a deficient number, since it is larger than the sum of its proper divisors (2674979).

398549521 is a wasteful number, since it uses less digits than its factorization.

398549521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2674978.

The product of its digits is 388800, while the sum is 46.

The square root of 398549521 is about 19963.7050919913. The cubic root of 398549521 is about 735.9146193342.

The spelling of 398549521 in words is "three hundred ninety-eight million, five hundred forty-nine thousand, five hundred twenty-one".