18723333857 has 2 divisors, whose sum is σ = 18723333858. Its totient is φ = 18723333856.

The previous prime is 18723333833. The next prime is 18723333899. The reversal of 18723333857 is 75833332781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18203676241 + 519657616 = 134921^2 + 22796^2 .

It is an emirp because it is prime and its reverse (75833332781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18723333857 - 2²² = 18719139553 is a prime.

It is not a weakly prime, because it can be changed into another prime (18723333157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9361666928 + 9361666929.

It is an arithmetic number, because the mean of its divisors is an integer number (9361666929).

Almost surely, 2^18723333857 is an apocalyptic number.

It is an amenable number.

18723333857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18723333857 is an equidigital number, since it uses as much as digits as its factorization.

18723333857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2540160, while the sum is 50.

The spelling of 18723333857 in words is "eighteen billion, seven hundred twenty-three million, three hundred thirty-three thousand, eight hundred fifty-seven".