398019961 has 4 divisors (see below), whose sum is σ = 418968400. Its totient is φ = 377071524.

The previous prime is 398019949. The next prime is 398019971. The reversal of 398019961 is 169910893.

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, and also an emirpimes, since its reverse is a distinct semiprime: 169910893 = 4283 ⋅39671.

It is a cyclic number.

It is not a de Polignac number, because 398019961 - 2⁷ = 398019833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398019971) 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, 10474191 + ... + 10474228.

It is an arithmetic number, because the mean of its divisors is an integer number (104742100).

Almost surely, 2^398019961 is an apocalyptic number.

It is an amenable number.

398019961 is a deficient number, since it is larger than the sum of its proper divisors (20948439).

398019961 is a wasteful number, since it uses less digits than its factorization.

398019961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20948438.

The product of its (nonzero) digits is 104976, while the sum is 46.

The square root of 398019961 is about 19950.4376142480. The cubic root of 398019961 is about 735.5885338182.

The spelling of 398019961 in words is "three hundred ninety-eight million, nineteen thousand, nine hundred sixty-one".