18985513 has 2 divisors, whose sum is σ = 18985514. Its totient is φ = 18985512.

The previous prime is 18985451. The next prime is 18985529. The reversal of 18985513 is 31558981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13046544 + 5938969 = 3612^2 + 2437^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18985513 is a prime.

It is not a weakly prime, because it can be changed into another prime (18985543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9492756 + 9492757.

It is an arithmetic number, because the mean of its divisors is an integer number (9492757).

Almost surely, 2^18985513 is an apocalyptic number.

It is an amenable number.

18985513 is a deficient number, since it is larger than the sum of its proper divisors (1).

18985513 is an equidigital number, since it uses as much as digits as its factorization.

18985513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43200, while the sum is 40.

The square root of 18985513 is about 4357.2368537870. The cubic root of 18985513 is about 266.7723280935.

The spelling of 18985513 in words is "eighteen million, nine hundred eighty-five thousand, five hundred thirteen".