218147857 has 2 divisors, whose sum is σ = 218147858. Its totient is φ = 218147856.

The previous prime is 218147843. The next prime is 218147861. The reversal of 218147857 is 758741812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 217739536 + 408321 = 14756^2 + 639^2 .

It is a cyclic number.

It is not a de Polignac number, because 218147857 - 2¹⁵ = 218115089 is a prime.

It is not a weakly prime, because it can be changed into another prime (218147827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109073928 + 109073929.

It is an arithmetic number, because the mean of its divisors is an integer number (109073929).

Almost surely, 2^218147857 is an apocalyptic number.

It is an amenable number.

218147857 is a deficient number, since it is larger than the sum of its proper divisors (1).

218147857 is an equidigital number, since it uses as much as digits as its factorization.

218147857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 125440, while the sum is 43.

The square root of 218147857 is about 14769.8292813424. The cubic root of 218147857 is about 601.9822007372.

The spelling of 218147857 in words is "two hundred eighteen million, one hundred forty-seven thousand, eight hundred fifty-seven".