18956555624197 has 2 divisors, whose sum is σ = 18956555624198. Its totient is φ = 18956555624196.

The previous prime is 18956555624159. The next prime is 18956555624213. The reversal of 18956555624197 is 79142655565981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17094842737281 + 1861712886916 = 4134591^2 + 1364446^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18956555624197 is a prime.

It is a super-2 number, since 2×18956555624197² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18956555622197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9478277812098 + 9478277812099.

It is an arithmetic number, because the mean of its divisors is an integer number (9478277812099).

Almost surely, 2^{18956555624197} is an apocalyptic number.

It is an amenable number.

18956555624197 is a deficient number, since it is larger than the sum of its proper divisors (1).

18956555624197 is an equidigital number, since it uses as much as digits as its factorization.

18956555624197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480000, while the sum is 73.

The spelling of 18956555624197 in words is "eighteen trillion, nine hundred fifty-six billion, five hundred fifty-five million, six hundred twenty-four thousand, one hundred ninety-seven".