18897397 has 4 divisors (see below), whose sum is σ = 18918880. Its totient is φ = 18875916.

The previous prime is 18897391. The next prime is 18897449. The reversal of 18897397 is 79379881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18897397 - 2²³ = 10508789 is a prime.

It is a super-2 number, since 2×18897397² = 714223226751218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18897391) 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, 9363 + ... + 11200.

It is an arithmetic number, because the mean of its divisors is an integer number (4729720).

Almost surely, 2^18897397 is an apocalyptic number.

It is an amenable number.

18897397 is a deficient number, since it is larger than the sum of its proper divisors (21483).

18897397 is an equidigital number, since it uses as much as digits as its factorization.

18897397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21482.

The product of its digits is 762048, while the sum is 52.

The square root of 18897397 is about 4347.1136401065. The cubic root of 18897397 is about 266.3589713152.

The spelling of 18897397 in words is "eighteen million, eight hundred ninety-seven thousand, three hundred ninety-seven".