18887775331 has 2 divisors, whose sum is σ = 18887775332. Its totient is φ = 18887775330.

The previous prime is 18887775289. The next prime is 18887775337. The reversal of 18887775331 is 13357778881.

It is a strong prime.

It is an emirp because it is prime and its reverse (13357778881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18887775331 - 2⁹ = 18887774819 is a prime.

It is a super-2 number, since 2×18887775331² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18887775337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9443887665 + 9443887666.

It is an arithmetic number, because the mean of its divisors is an integer number (9443887666).

Almost surely, 2^18887775331 is an apocalyptic number.

18887775331 is a deficient number, since it is larger than the sum of its proper divisors (1).

18887775331 is an equidigital number, since it uses as much as digits as its factorization.

18887775331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7902720, while the sum is 58.

The spelling of 18887775331 in words is "eighteen billion, eight hundred eighty-seven million, seven hundred seventy-five thousand, three hundred thirty-one".