1998239357 has 4 divisors (see below), whose sum is σ = 2040755136. Its totient is φ = 1955723580.

The previous prime is 1998239311. The next prime is 1998239389. The reversal of 1998239357 is 7539328991.

It is a happy number.

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.

It is not a de Polignac number, because 1998239357 - 2¹⁴ = 1998222973 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 (1998230357) 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, 21257819 + ... + 21257912.

It is an arithmetic number, because the mean of its divisors is an integer number (510188784).

Almost surely, 2^1998239357 is an apocalyptic number.

It is an amenable number.

1998239357 is a deficient number, since it is larger than the sum of its proper divisors (42515779).

1998239357 is an equidigital number, since it uses as much as digits as its factorization.

1998239357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42515778.

The product of its digits is 3674160, while the sum is 56.

The square root of 1998239357 is about 44701.6706287360. The cubic root of 1998239357 is about 1259.5512294905.

The spelling of 1998239357 in words is "one billion, nine hundred ninety-eight million, two hundred thirty-nine thousand, three hundred fifty-seven".