18904397 has 2 divisors, whose sum is σ = 18904398. Its totient is φ = 18904396.

The previous prime is 18904381. The next prime is 18904409. The reversal of 18904397 is 79340981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10719076 + 8185321 = 3274^2 + 2861^2 .

It is a cyclic number.

It is not a de Polignac number, because 18904397 - 2⁴ = 18904381 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 (18904997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9452198 + 9452199.

It is an arithmetic number, because the mean of its divisors is an integer number (9452199).

Almost surely, 2^18904397 is an apocalyptic number.

It is an amenable number.

18904397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18904397 is an equidigital number, since it uses as much as digits as its factorization.

18904397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 18904397 is about 4347.9186974919. The cubic root of 18904397 is about 266.3918556084.

The spelling of 18904397 in words is "eighteen million, nine hundred four thousand, three hundred ninety-seven".