18916836181391 has 2 divisors, whose sum is σ = 18916836181392. Its totient is φ = 18916836181390.

The previous prime is 18916836181357. The next prime is 18916836181421. The reversal of 18916836181391 is 19318163861981.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18916836181391 is a prime.

It is a super-2 number, since 2×18916836181391² (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 (18916836181351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9458418090695 + 9458418090696.

It is an arithmetic number, because the mean of its divisors is an integer number (9458418090696).

Almost surely, 2^{18916836181391} is an apocalyptic number.

18916836181391 is a deficient number, since it is larger than the sum of its proper divisors (1).

18916836181391 is an equidigital number, since it uses as much as digits as its factorization.

18916836181391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13436928, while the sum is 65.

The spelling of 18916836181391 in words is "eighteen trillion, nine hundred sixteen billion, eight hundred thirty-six million, one hundred eighty-one thousand, three hundred ninety-one".