18919197 has 24 divisors (see below), whose sum is σ = 30813440. Its totient is φ = 11464200.

The previous prime is 18919189. The next prime is 18919213. The reversal of 18919197 is 79191981.

It is not a de Polignac number, because 18919197 - 2³ = 18919189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18919127) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 372 + ... + 6162.

Almost surely, 2^18919197 is an apocalyptic number.

It is an amenable number.

18919197 is a deficient number, since it is larger than the sum of its proper divisors (11894243).

18919197 is a wasteful number, since it uses less digits than its factorization.

18919197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5822 (or 5805 counting only the distinct ones).

The product of its digits is 40824, while the sum is 45.

The square root of 18919197 is about 4349.6203282585. The cubic root of 18919197 is about 266.4613556836.

It can be divided in two parts, 1 and 8919197, that added together give a palindrome (8919198).

The spelling of 18919197 in words is "eighteen million, nine hundred nineteen thousand, one hundred ninety-seven".