18628397 has 2 divisors, whose sum is σ = 18628398. Its totient is φ = 18628396.

The previous prime is 18628373. The next prime is 18628399. The reversal of 18628397 is 79382681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14523721 + 4104676 = 3811^2 + 2026^2 .

It is a cyclic number.

It is not a de Polignac number, because 18628397 - 2¹² = 18624301 is a prime.

Together with 18628399, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18628399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9314198 + 9314199.

It is an arithmetic number, because the mean of its divisors is an integer number (9314199).

Almost surely, 2^18628397 is an apocalyptic number.

It is an amenable number.

18628397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18628397 is an equidigital number, since it uses as much as digits as its factorization.

18628397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The square root of 18628397 is about 4316.0626733170. The cubic root of 18628397 is about 265.0890741265.

The spelling of 18628397 in words is "eighteen million, six hundred twenty-eight thousand, three hundred ninety-seven".