18488557 has 2 divisors, whose sum is σ = 18488558. Its totient is φ = 18488556.

The previous prime is 18488549. The next prime is 18488579. The reversal of 18488557 is 75588481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18224361 + 264196 = 4269^2 + 514^2 .

It is an emirp because it is prime and its reverse (75588481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18488557 - 2³ = 18488549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18488857) 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, 9244278 + 9244279.

It is an arithmetic number, because the mean of its divisors is an integer number (9244279).

Almost surely, 2^18488557 is an apocalyptic number.

It is an amenable number.

18488557 is a deficient number, since it is larger than the sum of its proper divisors (1).

18488557 is an equidigital number, since it uses as much as digits as its factorization.

18488557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 358400, while the sum is 46.

The square root of 18488557 is about 4299.8322060285. The cubic root of 18488557 is about 264.4240821375.

The spelling of 18488557 in words is "eighteen million, four hundred eighty-eight thousand, five hundred fifty-seven".