18715493 has 2 divisors, whose sum is σ = 18715494. Its totient is φ = 18715492.

The previous prime is 18715481. The next prime is 18715547. The reversal of 18715493 is 39451781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10975969 + 7739524 = 3313^2 + 2782^2 .

It is a cyclic number.

It is not a de Polignac number, because 18715493 - 2¹⁰ = 18714469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18715423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9357746 + 9357747.

It is an arithmetic number, because the mean of its divisors is an integer number (9357747).

Almost surely, 2^18715493 is an apocalyptic number.

It is an amenable number.

18715493 is a deficient number, since it is larger than the sum of its proper divisors (1).

18715493 is an equidigital number, since it uses as much as digits as its factorization.

18715493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 38.

The square root of 18715493 is about 4326.1406588321. The cubic root of 18715493 is about 265.5015681745.

The spelling of 18715493 in words is "eighteen million, seven hundred fifteen thousand, four hundred ninety-three".