18726508081 has 2 divisors, whose sum is σ = 18726508082. Its totient is φ = 18726508080.

The previous prime is 18726508061. The next prime is 18726508103. The reversal of 18726508081 is 18080562781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18202327056 + 524181025 = 134916^2 + 22895^2 .

It is a cyclic number.

It is not a de Polignac number, because 18726508081 - 2¹¹ = 18726506033 is a prime.

It is a super-2 number, since 2×18726508081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18726508051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9363254040 + 9363254041.

It is an arithmetic number, because the mean of its divisors is an integer number (9363254041).

Almost surely, 2^18726508081 is an apocalyptic number.

It is an amenable number.

18726508081 is a deficient number, since it is larger than the sum of its proper divisors (1).

18726508081 is an equidigital number, since it uses as much as digits as its factorization.

18726508081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 215040, while the sum is 46.

The spelling of 18726508081 in words is "eighteen billion, seven hundred twenty-six million, five hundred eight thousand, eighty-one".