918664181 has 2 divisors, whose sum is σ = 918664182. Its totient is φ = 918664180.

The previous prime is 918664171. The next prime is 918664189. The reversal of 918664181 is 181466819.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 730837156 + 187827025 = 27034^2 + 13705^2 .

It is an emirp because it is prime and its reverse (181466819) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 918664181 - 2¹⁰ = 918663157 is a prime.

It is a super-2 number, since 2×918664181² = 1687887754904801522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (918664189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459332090 + 459332091.

It is an arithmetic number, because the mean of its divisors is an integer number (459332091).

Almost surely, 2^918664181 is an apocalyptic number.

It is an amenable number.

918664181 is a deficient number, since it is larger than the sum of its proper divisors (1).

918664181 is an equidigital number, since it uses as much as digits as its factorization.

918664181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 44.

The square root of 918664181 is about 30309.4734530311. The cubic root of 918664181 is about 972.1178726155.

The spelling of 918664181 in words is "nine hundred eighteen million, six hundred sixty-four thousand, one hundred eighty-one".