1998615793 has 4 divisors (see below), whose sum is σ = 1999466100. Its totient is φ = 1997765488.

The previous prime is 1998615781. The next prime is 1998615799. The reversal of 1998615793 is 3975168991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3975168991 = 1787 ⋅2224493.

It can be written as a sum of positive squares in 2 ways, for example, as 186240609 + 1812375184 = 13647^2 + 42572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998615793 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1998615799) 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, 421618 + ... + 426331.

It is an arithmetic number, because the mean of its divisors is an integer number (499866525).

Almost surely, 2^1998615793 is an apocalyptic number.

It is an amenable number.

1998615793 is a deficient number, since it is larger than the sum of its proper divisors (850307).

1998615793 is an equidigital number, since it uses as much as digits as its factorization.

1998615793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850306.

The product of its digits is 3674160, while the sum is 58.

The square root of 1998615793 is about 44705.8809666021. The cubic root of 1998615793 is about 1259.6303175561.

The spelling of 1998615793 in words is "one billion, nine hundred ninety-eight million, six hundred fifteen thousand, seven hundred ninety-three".