20768549 has 2 divisors, whose sum is σ = 20768550. Its totient is φ = 20768548.

The previous prime is 20768497. The next prime is 20768551. The reversal of 20768549 is 94586702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20702500 + 66049 = 4550^2 + 257^2 .

It is a cyclic number.

It is not a de Polignac number, because 20768549 - 2²⁴ = 3991333 is a prime.

It is a Sophie Germain prime.

Together with 20768551, it forms a pair of twin primes.

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 (20768569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10384274 + 10384275.

It is an arithmetic number, because the mean of its divisors is an integer number (10384275).

Almost surely, 2^20768549 is an apocalyptic number.

It is an amenable number.

20768549 is a deficient number, since it is larger than the sum of its proper divisors (1).

20768549 is an equidigital number, since it uses as much as digits as its factorization.

20768549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 20768549 is about 4557.2523520209. The cubic root of 20768549 is about 274.8750903800.

The spelling of 20768549 in words is "twenty million, seven hundred sixty-eight thousand, five hundred forty-nine".