18725128187 has 4 divisors (see below), whose sum is σ = 18890837400. Its totient is φ = 18559418976.

The previous prime is 18725128157. The next prime is 18725128237. The reversal of 18725128187 is 78182152781.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78182152781 = 103 ⋅759050027.

It is a cyclic number.

It is not a de Polignac number, because 18725128187 - 2³⁴ = 1545259003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18725128157) 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, 82854437 + ... + 82854662.

It is an arithmetic number, because the mean of its divisors is an integer number (4722709350).

Almost surely, 2^18725128187 is an apocalyptic number.

18725128187 is a deficient number, since it is larger than the sum of its proper divisors (165709213).

18725128187 is a wasteful number, since it uses less digits than its factorization.

18725128187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165709212.

The product of its digits is 501760, while the sum is 50.

The spelling of 18725128187 in words is "eighteen billion, seven hundred twenty-five million, one hundred twenty-eight thousand, one hundred eighty-seven".