18257830321 has 2 divisors, whose sum is σ = 18257830322. Its totient is φ = 18257830320.

The previous prime is 18257830271. The next prime is 18257830333. The reversal of 18257830321 is 12303875281.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17400511921 + 857318400 = 131911^2 + 29280^2 .

It is a cyclic number.

It is not a de Polignac number, because 18257830321 - 2⁷ = 18257830193 is a prime.

It is a super-4 number, since 4×18257830321⁴ (a number of 42 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (18257830351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9128915160 + 9128915161.

It is an arithmetic number, because the mean of its divisors is an integer number (9128915161).

Almost surely, 2^18257830321 is an apocalyptic number.

It is an amenable number.

18257830321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18257830321 is an equidigital number, since it uses as much as digits as its factorization.

18257830321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 18257830321 in words is "eighteen billion, two hundred fifty-seven million, eight hundred thirty thousand, three hundred twenty-one".