18048729221 has 2 divisors, whose sum is σ = 18048729222. Its totient is φ = 18048729220.

The previous prime is 18048729203. The next prime is 18048729277. The reversal of 18048729221 is 12292784081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12992808196 + 5055921025 = 113986^2 + 71105^2 .

It is a cyclic number.

It is not a de Polignac number, because 18048729221 - 2⁶ = 18048729157 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18048729421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9024364610 + 9024364611.

It is an arithmetic number, because the mean of its divisors is an integer number (9024364611).

Almost surely, 2^18048729221 is an apocalyptic number.

It is an amenable number.

18048729221 is a deficient number, since it is larger than the sum of its proper divisors (1).

18048729221 is an equidigital number, since it uses as much as digits as its factorization.

18048729221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129024, while the sum is 44.

The spelling of 18048729221 in words is "eighteen billion, forty-eight million, seven hundred twenty-nine thousand, two hundred twenty-one".