18189497 has 4 divisors (see below), whose sum is σ = 18350580. Its totient is φ = 18028416.

The previous prime is 18189487. The next prime is 18189539. The reversal of 18189497 is 79498181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1510441 + 16679056 = 1229^2 + 4084^2 .

It is a cyclic number.

It is not a de Polignac number, because 18189497 - 2⁶ = 18189433 is a prime.

It is a super-2 number, since 2×18189497² = 661715602226018, which contains 22 as substring.

It is a pancake number, because a pancake can be divided into 18189497 parts by 6031 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18189427) 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, 80372 + ... + 80597.

It is an arithmetic number, because the mean of its divisors is an integer number (4587645).

Almost surely, 2^18189497 is an apocalyptic number.

It is an amenable number.

18189497 is a deficient number, since it is larger than the sum of its proper divisors (161083).

18189497 is a wasteful number, since it uses less digits than its factorization.

18189497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161082.

The product of its digits is 145152, while the sum is 47.

The square root of 18189497 is about 4264.9146533078. The cubic root of 18189497 is about 262.9906023909.

The spelling of 18189497 in words is "eighteen million, one hundred eighty-nine thousand, four hundred ninety-seven".