18978897 has 8 divisors (see below), whose sum is σ = 28920256. Its totient is φ = 10845072.

The previous prime is 18978893. The next prime is 18978901. The reversal of 18978897 is 79887981.

It is an interprime number because it is at equal distance from previous prime (18978893) and next prime (18978901).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18978897 - 2² = 18978893 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18978893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 451858 + ... + 451899.

It is an arithmetic number, because the mean of its divisors is an integer number (3615032).

Almost surely, 2^18978897 is an apocalyptic number.

It is an amenable number.

18978897 is a deficient number, since it is larger than the sum of its proper divisors (9941359).

18978897 is an equidigital number, since it uses as much as digits as its factorization.

18978897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903767.

The product of its digits is 2032128, while the sum is 57.

The square root of 18978897 is about 4356.4775908984. The cubic root of 18978897 is about 266.7413365549.

The spelling of 18978897 in words is "eighteen million, nine hundred seventy-eight thousand, eight hundred ninety-seven".