18003460721 has 2 divisors, whose sum is σ = 18003460722. Its totient is φ = 18003460720.

The previous prime is 18003460663. The next prime is 18003460771. The reversal of 18003460721 is 12706430081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12151975696 + 5851485025 = 110236^2 + 76495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18003460721 is a prime.

It is not a weakly prime, because it can be changed into another prime (18003460771) 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, 9001730360 + 9001730361.

It is an arithmetic number, because the mean of its divisors is an integer number (9001730361).

Almost surely, 2^18003460721 is an apocalyptic number.

It is an amenable number.

18003460721 is a deficient number, since it is larger than the sum of its proper divisors (1).

18003460721 is an equidigital number, since it uses as much as digits as its factorization.

18003460721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The spelling of 18003460721 in words is "eighteen billion, three million, four hundred sixty thousand, seven hundred twenty-one".