218091473 has 2 divisors, whose sum is σ = 218091474. Its totient is φ = 218091472.

The previous prime is 218091457. The next prime is 218091491. The reversal of 218091473 is 374190812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148669249 + 69422224 = 12193^2 + 8332^2 .

It is a cyclic number.

It is not a de Polignac number, because 218091473 - 2⁴ = 218091457 is a prime.

It is not a weakly prime, because it can be changed into another prime (218091413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109045736 + 109045737.

It is an arithmetic number, because the mean of its divisors is an integer number (109045737).

Almost surely, 2^218091473 is an apocalyptic number.

It is an amenable number.

218091473 is a deficient number, since it is larger than the sum of its proper divisors (1).

218091473 is an equidigital number, since it uses as much as digits as its factorization.

218091473 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 218091473 is about 14767.9204020065. The cubic root of 218091473 is about 601.9303321107.

The spelling of 218091473 in words is "two hundred eighteen million, ninety-one thousand, four hundred seventy-three".