18987391337 has 4 divisors (see below), whose sum is σ = 19254819456. Its totient is φ = 18719963220.

The previous prime is 18987391259. The next prime is 18987391427. The reversal of 18987391337 is 73319378981.

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 a cyclic number.

It is not a de Polignac number, because 18987391337 - 2¹² = 18987387241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18987321337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133713953 + ... + 133714094.

It is an arithmetic number, because the mean of its divisors is an integer number (4813704864).

Almost surely, 2^18987391337 is an apocalyptic number.

It is an amenable number.

18987391337 is a deficient number, since it is larger than the sum of its proper divisors (267428119).

18987391337 is an equidigital number, since it uses as much as digits as its factorization.

18987391337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267428118.

The product of its digits is 6858432, while the sum is 59.

The spelling of 18987391337 in words is "eighteen billion, nine hundred eighty-seven million, three hundred ninety-one thousand, three hundred thirty-seven".