20719729 has 2 divisors, whose sum is σ = 20719730. Its totient is φ = 20719728.

The previous prime is 20719723. The next prime is 20719739. The reversal of 20719729 is 92791702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10575504 + 10144225 = 3252^2 + 3185^2 .

It is a cyclic number.

It is not a de Polignac number, because 20719729 - 2⁵ = 20719697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20719723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10359864 + 10359865.

It is an arithmetic number, because the mean of its divisors is an integer number (10359865).

Almost surely, 2^20719729 is an apocalyptic number.

It is an amenable number.

20719729 is a deficient number, since it is larger than the sum of its proper divisors (1).

20719729 is an equidigital number, since it uses as much as digits as its factorization.

20719729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 20719729 is about 4551.8929029581. The cubic root of 20719729 is about 274.6595412095.

The spelling of 20719729 in words is "twenty million, seven hundred nineteen thousand, seven hundred twenty-nine".