218251949 has 2 divisors, whose sum is σ = 218251950. Its totient is φ = 218251948.

The previous prime is 218251939. The next prime is 218251987. The reversal of 218251949 is 949152812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176092900 + 42159049 = 13270^2 + 6493^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218251949 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 (218251939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109125974 + 109125975.

It is an arithmetic number, because the mean of its divisors is an integer number (109125975).

Almost surely, 2^218251949 is an apocalyptic number.

It is an amenable number.

218251949 is a deficient number, since it is larger than the sum of its proper divisors (1).

218251949 is an equidigital number, since it uses as much as digits as its factorization.

218251949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 41.

The square root of 218251949 is about 14773.3526662028. The cubic root of 218251949 is about 602.0779333107.

The spelling of 218251949 in words is "two hundred eighteen million, two hundred fifty-one thousand, nine hundred forty-nine".