18348235921 has 2 divisors, whose sum is σ = 18348235922. Its totient is φ = 18348235920.

The previous prime is 18348235907. The next prime is 18348235937. The reversal of 18348235921 is 12953284381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17625217600 + 723018321 = 132760^2 + 26889^2 .

It is an emirp because it is prime and its reverse (12953284381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18348235921 - 2⁷ = 18348235793 is a prime.

It is a super-2 number, since 2×18348235921² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18348235981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9174117960 + 9174117961.

It is an arithmetic number, because the mean of its divisors is an integer number (9174117961).

Almost surely, 2^18348235921 is an apocalyptic number.

It is an amenable number.

18348235921 is a deficient number, since it is larger than the sum of its proper divisors (1).

18348235921 is an equidigital number, since it uses as much as digits as its factorization.

18348235921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 414720, while the sum is 46.

The spelling of 18348235921 in words is "eighteen billion, three hundred forty-eight million, two hundred thirty-five thousand, nine hundred twenty-one".