18407517881 has 2 divisors, whose sum is σ = 18407517882. Its totient is φ = 18407517880.

The previous prime is 18407517859. The next prime is 18407517883. The reversal of 18407517881 is 18871570481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14194339600 + 4213178281 = 119140^2 + 64909^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18407517881 is a prime.

It is a super-2 number, since 2×18407517881² (a number of 21 digits) contains 22 as substring.

Together with 18407517883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18407517883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9203758940 + 9203758941.

It is an arithmetic number, because the mean of its divisors is an integer number (9203758941).

Almost surely, 2^18407517881 is an apocalyptic number.

It is an amenable number.

18407517881 is a deficient number, since it is larger than the sum of its proper divisors (1).

18407517881 is an equidigital number, since it uses as much as digits as its factorization.

18407517881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 501760, while the sum is 50.

The spelling of 18407517881 in words is "eighteen billion, four hundred seven million, five hundred seventeen thousand, eight hundred eighty-one".