20071729 has 2 divisors, whose sum is σ = 20071730. Its totient is φ = 20071728.

The previous prime is 20071721. The next prime is 20071757. The reversal of 20071729 is 92717002.

It is a happy number.

It is an a-pointer prime, because the next prime (20071757) can be obtained adding 20071729 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17447329 + 2624400 = 4177^2 + 1620^2 .

It is a cyclic number.

It is not a de Polignac number, because 20071729 - 2³ = 20071721 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20071697 and 20071706.

It is not a weakly prime, because it can be changed into another prime (20071721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10035864 + 10035865.

It is an arithmetic number, because the mean of its divisors is an integer number (10035865).

Almost surely, 2^20071729 is an apocalyptic number.

It is an amenable number.

20071729 is a deficient number, since it is larger than the sum of its proper divisors (1).

20071729 is an equidigital number, since it uses as much as digits as its factorization.

20071729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 20071729 is about 4480.1483234375. The cubic root of 20071729 is about 271.7658785934.

The spelling of 20071729 in words is "twenty million, seventy-one thousand, seven hundred twenty-nine".