18663554957 has 2 divisors, whose sum is σ = 18663554958. Its totient is φ = 18663554956.

The previous prime is 18663554947. The next prime is 18663554983. The reversal of 18663554957 is 75945536681.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12462149956 + 6201405001 = 111634^2 + 78749^2 .

It is a cyclic number.

It is not a de Polignac number, because 18663554957 - 2⁶ = 18663554893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18663554896 and 18663554905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18663554947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9331777478 + 9331777479.

It is an arithmetic number, because the mean of its divisors is an integer number (9331777479).

Almost surely, 2^18663554957 is an apocalyptic number.

It is an amenable number.

18663554957 is a deficient number, since it is larger than the sum of its proper divisors (1).

18663554957 is an equidigital number, since it uses as much as digits as its factorization.

18663554957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216000, while the sum is 59.

The spelling of 18663554957 in words is "eighteen billion, six hundred sixty-three million, five hundred fifty-four thousand, nine hundred fifty-seven".