18530381387 has 4 divisors (see below), whose sum is σ = 21177578736. Its totient is φ = 15883184040.

The previous prime is 18530381371. The next prime is 18530381407. The reversal of 18530381387 is 78318303581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78318303581 = 7 ⋅11188329083.

It is a cyclic number.

It is not a de Polignac number, because 18530381387 - 2⁴ = 18530381371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18530381087) 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, 1323598664 + ... + 1323598677.

It is an arithmetic number, because the mean of its divisors is an integer number (5294394684).

Almost surely, 2^18530381387 is an apocalyptic number.

18530381387 is a deficient number, since it is larger than the sum of its proper divisors (2647197349).

18530381387 is an equidigital number, since it uses as much as digits as its factorization.

18530381387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2647197348.

The product of its (nonzero) digits is 483840, while the sum is 47.

The spelling of 18530381387 in words is "eighteen billion, five hundred thirty million, three hundred eighty-one thousand, three hundred eighty-seven".