18847397 has 2 divisors, whose sum is σ = 18847398. Its totient is φ = 18847396.

The previous prime is 18847343. The next prime is 18847403. The reversal of 18847397 is 79374881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17522596 + 1324801 = 4186^2 + 1151^2 .

It is a cyclic number.

It is not a de Polignac number, because 18847397 - 2⁶ = 18847333 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18847337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9423698 + 9423699.

It is an arithmetic number, because the mean of its divisors is an integer number (9423699).

Almost surely, 2^18847397 is an apocalyptic number.

It is an amenable number.

18847397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18847397 is an equidigital number, since it uses as much as digits as its factorization.

18847397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 338688, while the sum is 47.

The square root of 18847397 is about 4341.3588886430. The cubic root of 18847397 is about 266.1238470156.

The spelling of 18847397 in words is "eighteen million, eight hundred forty-seven thousand, three hundred ninety-seven".