20705767 has 2 divisors, whose sum is σ = 20705768. Its totient is φ = 20705766.

The previous prime is 20705753. The next prime is 20705777. The reversal of 20705767 is 76750702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20705767 - 2⁷ = 20705639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20705777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10352883 + 10352884.

It is an arithmetic number, because the mean of its divisors is an integer number (10352884).

Almost surely, 2^20705767 is an apocalyptic number.

20705767 is a deficient number, since it is larger than the sum of its proper divisors (1).

20705767 is an equidigital number, since it uses as much as digits as its factorization.

20705767 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20580, while the sum is 34.

The square root of 20705767 is about 4550.3589968265. The cubic root of 20705767 is about 274.5978341895.

The spelling of 20705767 in words is "twenty million, seven hundred five thousand, seven hundred sixty-seven".