18725578 has 4 divisors (see below), whose sum is σ = 28088370. Its totient is φ = 9362788.

The previous prime is 18725573. The next prime is 18725579. The reversal of 18725578 is 87552781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87552781 = 103 ⋅850027.

It can be written as a sum of positive squares in only one way, i.e., 18688329 + 37249 = 4323^2 + 193^2 .

It is not an unprimeable number, because it can be changed into a prime (18725573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4681393 + ... + 4681396.

Almost surely, 2^18725578 is an apocalyptic number.

18725578 is a deficient number, since it is larger than the sum of its proper divisors (9362792).

18725578 is an equidigital number, since it uses as much as digits as its factorization.

18725578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9362791.

The product of its digits is 156800, while the sum is 43.

The square root of 18725578 is about 4327.3060903985. The cubic root of 18725578 is about 265.5492488583.

The spelling of 18725578 in words is "eighteen million, seven hundred twenty-five thousand, five hundred seventy-eight".