18321312253 has 2 divisors, whose sum is σ = 18321312254. Its totient is φ = 18321312252.

The previous prime is 18321312209. The next prime is 18321312257. The reversal of 18321312253 is 35221312381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13646445124 + 4674867129 = 116818^2 + 68373^2 .

It is an emirp because it is prime and its reverse (35221312381) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18321312253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18321312257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9160656126 + 9160656127.

It is an arithmetic number, because the mean of its divisors is an integer number (9160656127).

Almost surely, 2^18321312253 is an apocalyptic number.

It is an amenable number.

18321312253 is a deficient number, since it is larger than the sum of its proper divisors (1).

18321312253 is an equidigital number, since it uses as much as digits as its factorization.

18321312253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 31.

The spelling of 18321312253 in words is "eighteen billion, three hundred twenty-one million, three hundred twelve thousand, two hundred fifty-three".