18919534 has 4 divisors (see below), whose sum is σ = 28379304. Its totient is φ = 9459766.

The previous prime is 18919529. The next prime is 18919541. The reversal of 18919534 is 43591981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 43591981 = 43 ⋅1013767.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4729882 + ... + 4729885.

It is an arithmetic number, because the mean of its divisors is an integer number (7094826).

Almost surely, 2^18919534 is an apocalyptic number.

18919534 is a deficient number, since it is larger than the sum of its proper divisors (9459770).

18919534 is an equidigital number, since it uses as much as digits as its factorization.

18919534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9459769.

The product of its digits is 38880, while the sum is 40.

The square root of 18919534 is about 4349.6590670994. The cubic root of 18919534 is about 266.4629377970.

The spelling of 18919534 in words is "eighteen million, nine hundred nineteen thousand, five hundred thirty-four".