20268749 has 2 divisors, whose sum is σ = 20268750. Its totient is φ = 20268748.

The previous prime is 20268733. The next prime is 20268757. The reversal of 20268749 is 94786202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10843849 + 9424900 = 3293^2 + 3070^2 .

It is a cyclic number.

It is not a de Polignac number, because 20268749 - 2⁴ = 20268733 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20268769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10134374 + 10134375.

It is an arithmetic number, because the mean of its divisors is an integer number (10134375).

Almost surely, 2^20268749 is an apocalyptic number.

It is an amenable number.

20268749 is a deficient number, since it is larger than the sum of its proper divisors (1).

20268749 is an equidigital number, since it uses as much as digits as its factorization.

20268749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 20268749 is about 4502.0827402437. The cubic root of 20268749 is about 272.6521844428.

The spelling of 20268749 in words is "twenty million, two hundred sixty-eight thousand, seven hundred forty-nine".