1998401259 has 4 divisors (see below), whose sum is σ = 2664535016. Its totient is φ = 1332267504.

The previous prime is 1998401257. The next prime is 1998401309. The reversal of 1998401259 is 9521048991.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1998401259 - 2¹ = 1998401257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1998401257) 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, 333066874 + ... + 333066879.

It is an arithmetic number, because the mean of its divisors is an integer number (666133754).

Almost surely, 2^1998401259 is an apocalyptic number.

1998401259 is a deficient number, since it is larger than the sum of its proper divisors (666133757).

1998401259 is an equidigital number, since it uses as much as digits as its factorization.

1998401259 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666133756.

The product of its (nonzero) digits is 233280, while the sum is 48.

The square root of 1998401259 is about 44703.4815087147. The cubic root of 1998401259 is about 1259.5852458285.

The spelling of 1998401259 in words is "one billion, nine hundred ninety-eight million, four hundred one thousand, two hundred fifty-nine".