18548681 has 2 divisors, whose sum is σ = 18548682. Its totient is φ = 18548680.

The previous prime is 18548671. The next prime is 18548701. The reversal of 18548681 is 18684581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18139081 + 409600 = 4259^2 + 640^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18548681 is a prime.

It is a super-2 number, since 2×18548681² = 688107133679522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18548641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9274340 + 9274341.

It is an arithmetic number, because the mean of its divisors is an integer number (9274341).

Almost surely, 2^18548681 is an apocalyptic number.

It is an amenable number.

18548681 is a deficient number, since it is larger than the sum of its proper divisors (1).

18548681 is an equidigital number, since it uses as much as digits as its factorization.

18548681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61440, while the sum is 41.

The square root of 18548681 is about 4306.8179668985. The cubic root of 18548681 is about 264.7104039441.

The spelling of 18548681 in words is "eighteen million, five hundred forty-eight thousand, six hundred eighty-one".