1800398399 has 4 divisors (see below), whose sum is σ = 1800662136. Its totient is φ = 1800134664.

The previous prime is 1800398381. The next prime is 1800398417. The reversal of 1800398399 is 9938930081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9938930081 = 251 ⋅39597331.

It is an interprime number because it is at equal distance from previous prime (1800398381) and next prime (1800398417).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1800398399 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 (1800397399) 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, 121349 + ... + 135374.

It is an arithmetic number, because the mean of its divisors is an integer number (450165534).

Almost surely, 2^1800398399 is an apocalyptic number.

1800398399 is a deficient number, since it is larger than the sum of its proper divisors (263737).

1800398399 is an equidigital number, since it uses as much as digits as its factorization.

1800398399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263736.

The product of its (nonzero) digits is 419904, while the sum is 50.

The square root of 1800398399 is about 42431.1017886644. The cubic root of 1800398399 is about 1216.5301385384.

The spelling of 1800398399 in words is "one billion, eight hundred million, three hundred ninety-eight thousand, three hundred ninety-nine".