19398989 has 8 divisors (see below), whose sum is σ = 21095928. Its totient is φ = 17763840.

The previous prime is 19398961. The next prime is 19398991. The reversal of 19398989 is 98989391.

It can be written as a sum of positive squares in 4 ways, for example, as 12482089 + 6916900 = 3533^2 + 2630^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19398989 - 2²⁰ = 18350413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19398889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14792 + ... + 16049.

It is an arithmetic number, because the mean of its divisors is an integer number (2636991).

Almost surely, 2^19398989 is an apocalyptic number.

It is an amenable number.

19398989 is a deficient number, since it is larger than the sum of its proper divisors (1696939).

19398989 is a wasteful number, since it uses less digits than its factorization.

19398989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30895.

The product of its digits is 1259712, while the sum is 56.

The square root of 19398989 is about 4404.4283397508. The cubic root of 19398989 is about 268.6950705117.

The spelling of 19398989 in words is "nineteen million, three hundred ninety-eight thousand, nine hundred eighty-nine".