18987853 has 2 divisors, whose sum is σ = 18987854. Its totient is φ = 18987852.

The previous prime is 18987803. The next prime is 18987863. The reversal of 18987853 is 35878981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17197609 + 1790244 = 4147^2 + 1338^2 .

It is an emirp because it is prime and its reverse (35878981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18987853 - 2⁹ = 18987341 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18987797 and 18987806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18987803) 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, 9493926 + 9493927.

It is an arithmetic number, because the mean of its divisors is an integer number (9493927).

Almost surely, 2^18987853 is an apocalyptic number.

It is an amenable number.

18987853 is a deficient number, since it is larger than the sum of its proper divisors (1).

18987853 is an equidigital number, since it uses as much as digits as its factorization.

18987853 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 49.

The square root of 18987853 is about 4357.5053643111. The cubic root of 18987853 is about 266.7832877061.

The spelling of 18987853 in words is "eighteen million, nine hundred eighty-seven thousand, eight hundred fifty-three".