18351318253 has 4 divisors (see below), whose sum is σ = 19430807580. Its totient is φ = 17271828928.

The previous prime is 18351318203. The next prime is 18351318277. The reversal of 18351318253 is 35281315381.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6961732969 + 11389585284 = 83437^2 + 106722^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18351318253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18351318203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 539744638 + ... + 539744671.

It is an arithmetic number, because the mean of its divisors is an integer number (4857701895).

Almost surely, 2^18351318253 is an apocalyptic number.

It is an amenable number.

18351318253 is a deficient number, since it is larger than the sum of its proper divisors (1079489327).

18351318253 is a wasteful number, since it uses less digits than its factorization.

18351318253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079489326.

The product of its digits is 86400, while the sum is 40.

The spelling of 18351318253 in words is "eighteen billion, three hundred fifty-one million, three hundred eighteen thousand, two hundred fifty-three".