218917949 has 2 divisors, whose sum is σ = 218917950. Its totient is φ = 218917948.

The previous prime is 218917913. The next prime is 218917957. The reversal of 218917949 is 949719812.

218917949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180042724 + 38875225 = 13418^2 + 6235^2 .

It is a cyclic number.

It is not a de Polignac number, because 218917949 - 2⁸ = 218917693 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 218917897 and 218917906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218917999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109458974 + 109458975.

It is an arithmetic number, because the mean of its divisors is an integer number (109458975).

Almost surely, 2^218917949 is an apocalyptic number.

It is an amenable number.

218917949 is a deficient number, since it is larger than the sum of its proper divisors (1).

218917949 is an equidigital number, since it uses as much as digits as its factorization.

218917949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 50.

The square root of 218917949 is about 14795.8760808544. The cubic root of 218917949 is about 602.6897288761.

The spelling of 218917949 in words is "two hundred eighteen million, nine hundred seventeen thousand, nine hundred forty-nine".