19731998 has 16 divisors (see below), whose sum is σ = 34772976. Its totient is φ = 8279040.

The previous prime is 19731997. The next prime is 19732003. The reversal of 19731998 is 89913791.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19731991) 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, 34211 + ... + 34782.

It is an arithmetic number, because the mean of its divisors is an integer number (2173311).

Almost surely, 2^19731998 is an apocalyptic number.

19731998 is a deficient number, since it is larger than the sum of its proper divisors (15040978).

19731998 is a wasteful number, since it uses less digits than its factorization.

19731998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69019.

The product of its digits is 122472, while the sum is 47.

The square root of 19731998 is about 4442.0713636771. The cubic root of 19731998 is about 270.2238564166.

The spelling of 19731998 in words is "nineteen million, seven hundred thirty-one thousand, nine hundred ninety-eight".