18810643349 has 2 divisors, whose sum is σ = 18810643350. Its totient is φ = 18810643348.

The previous prime is 18810643333. The next prime is 18810643351. The reversal of 18810643349 is 94334601881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13094224900 + 5716418449 = 114430^2 + 75607^2 .

It is a cyclic number.

It is not a de Polignac number, because 18810643349 - 2⁴ = 18810643333 is a prime.

Together with 18810643351, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18810643399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9405321674 + 9405321675.

It is an arithmetic number, because the mean of its divisors is an integer number (9405321675).

Almost surely, 2^18810643349 is an apocalyptic number.

It is an amenable number.

18810643349 is a deficient number, since it is larger than the sum of its proper divisors (1).

18810643349 is an equidigital number, since it uses as much as digits as its factorization.

18810643349 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 497664, while the sum is 47.

The spelling of 18810643349 in words is "eighteen billion, eight hundred ten million, six hundred forty-three thousand, three hundred forty-nine".