18183789521 has 2 divisors, whose sum is σ = 18183789522. Its totient is φ = 18183789520.

The previous prime is 18183789517. The next prime is 18183789523. The reversal of 18183789521 is 12598738181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14041065025 + 4142724496 = 118495^2 + 64364^2 .

It is a cyclic number.

It is not a de Polignac number, because 18183789521 - 2² = 18183789517 is a prime.

Together with 18183789523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18183789523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9091894760 + 9091894761.

It is an arithmetic number, because the mean of its divisors is an integer number (9091894761).

Almost surely, 2^18183789521 is an apocalyptic number.

It is an amenable number.

18183789521 is a deficient number, since it is larger than the sum of its proper divisors (1).

18183789521 is an equidigital number, since it uses as much as digits as its factorization.

18183789521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 967680, while the sum is 53.

The spelling of 18183789521 in words is "eighteen billion, one hundred eighty-three million, seven hundred eighty-nine thousand, five hundred twenty-one".