209968949 has 2 divisors, whose sum is σ = 209968950. Its totient is φ = 209968948.

The previous prime is 209968937. The next prime is 209969003. The reversal of 209968949 is 949869902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 146845924 + 63123025 = 12118^2 + 7945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209968949 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 209968894 and 209968903.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209968049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104984474 + 104984475.

It is an arithmetic number, because the mean of its divisors is an integer number (104984475).

Almost surely, 2^209968949 is an apocalyptic number.

It is an amenable number.

209968949 is a deficient number, since it is larger than the sum of its proper divisors (1).

209968949 is an equidigital number, since it uses as much as digits as its factorization.

209968949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2519424, while the sum is 56.

The square root of 209968949 is about 14490.3053452990. The cubic root of 209968949 is about 594.3628978449.

The spelling of 209968949 in words is "two hundred nine million, nine hundred sixty-eight thousand, nine hundred forty-nine".