18521431938011 has 2 divisors, whose sum is σ = 18521431938012. Its totient is φ = 18521431938010.

The previous prime is 18521431937993. The next prime is 18521431938067. The reversal of 18521431938011 is 11083913412581.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18521431938011 is a prime.

It is a super-2 number, since 2×18521431938011² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18521431935011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9260715969005 + 9260715969006.

It is an arithmetic number, because the mean of its divisors is an integer number (9260715969006).

Almost surely, 2^{18521431938011} is an apocalyptic number.

18521431938011 is a deficient number, since it is larger than the sum of its proper divisors (1).

18521431938011 is an equidigital number, since it uses as much as digits as its factorization.

18521431938011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 207360, while the sum is 47.

The spelling of 18521431938011 in words is "eighteen trillion, five hundred twenty-one billion, four hundred thirty-one million, nine hundred thirty-eight thousand, eleven".