18454387817 has 2 divisors, whose sum is σ = 18454387818. Its totient is φ = 18454387816.

The previous prime is 18454387753. The next prime is 18454387891. The reversal of 18454387817 is 71878345481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12405281641 + 6049106176 = 111379^2 + 77776^2 .

It is a cyclic number.

It is not a de Polignac number, because 18454387817 - 2⁶ = 18454387753 is a prime.

It is not a weakly prime, because it can be changed into another prime (18454387117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9227193908 + 9227193909.

It is an arithmetic number, because the mean of its divisors is an integer number (9227193909).

Almost surely, 2^18454387817 is an apocalyptic number.

It is an amenable number.

18454387817 is a deficient number, since it is larger than the sum of its proper divisors (1).

18454387817 is an equidigital number, since it uses as much as digits as its factorization.

18454387817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6021120, while the sum is 56.

The spelling of 18454387817 in words is "eighteen billion, four hundred fifty-four million, three hundred eighty-seven thousand, eight hundred seventeen".