18919539 has 6 divisors (see below), whose sum is σ = 27328236. Its totient is φ = 12613020.

The previous prime is 18919529. The next prime is 18919541. The reversal of 18919539 is 93591981.

It is not a de Polignac number, because 18919539 - 2⁵ = 18919507 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18919494 and 18919503.

It is not an unprimeable number, because it can be changed into a prime (18919519) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1051077 + ... + 1051094.

It is an arithmetic number, because the mean of its divisors is an integer number (4554706).

Almost surely, 2^18919539 is an apocalyptic number.

18919539 is a deficient number, since it is larger than the sum of its proper divisors (8408697).

18919539 is a wasteful number, since it uses less digits than its factorization.

18919539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102177 (or 2102174 counting only the distinct ones).

The product of its digits is 87480, while the sum is 45.

The square root of 18919539 is about 4349.6596418570. The cubic root of 18919539 is about 266.4629612703.

The spelling of 18919539 in words is "eighteen million, nine hundred nineteen thousand, five hundred thirty-nine".