218450261 has 2 divisors, whose sum is σ = 218450262. Its totient is φ = 218450260.

The previous prime is 218450209. The next prime is 218450269. The reversal of 218450261 is 162054812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121132036 + 97318225 = 11006^2 + 9865^2 .

It is a cyclic number.

It is not a de Polignac number, because 218450261 - 2¹⁰ = 218449237 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218450269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109225130 + 109225131.

It is an arithmetic number, because the mean of its divisors is an integer number (109225131).

Almost surely, 2^218450261 is an apocalyptic number.

It is an amenable number.

218450261 is a deficient number, since it is larger than the sum of its proper divisors (1).

218450261 is an equidigital number, since it uses as much as digits as its factorization.

218450261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 218450261 is about 14780.0629565642. The cubic root of 218450261 is about 602.2602350562.

The spelling of 218450261 in words is "two hundred eighteen million, four hundred fifty thousand, two hundred sixty-one".