20729771 has 2 divisors, whose sum is σ = 20729772. Its totient is φ = 20729770.

The previous prime is 20729747. The next prime is 20729789. The reversal of 20729771 is 17792702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20729771 - 2⁶ = 20729707 is a prime.

It is a Sophie Germain prime.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (20729701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10364885 + 10364886.

It is an arithmetic number, because the mean of its divisors is an integer number (10364886).

Almost surely, 2^20729771 is an apocalyptic number.

20729771 is a deficient number, since it is larger than the sum of its proper divisors (1).

20729771 is an equidigital number, since it uses as much as digits as its factorization.

20729771 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12348, while the sum is 35.

The square root of 20729771 is about 4552.9958269254. The cubic root of 20729771 is about 274.7039061020.

The spelling of 20729771 in words is "twenty million, seven hundred twenty-nine thousand, seven hundred seventy-one".