717719921 has 2 divisors, whose sum is σ = 717719922. Its totient is φ = 717719920.

The previous prime is 717719911. The next prime is 717719963. The reversal of 717719921 is 129917717.

717719921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 710755600 + 6964321 = 26660^2 + 2639^2 .

It is a cyclic number.

It is not a de Polignac number, because 717719921 - 2¹⁸ = 717457777 is a prime.

It is not a weakly prime, because it can be changed into another prime (717719911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 358859960 + 358859961.

It is an arithmetic number, because the mean of its divisors is an integer number (358859961).

Almost surely, 2^717719921 is an apocalyptic number.

It is an amenable number.

717719921 is a deficient number, since it is larger than the sum of its proper divisors (1).

717719921 is an equidigital number, since it uses as much as digits as its factorization.

717719921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55566, while the sum is 44.

The square root of 717719921 is about 26790.2952764616. The cubic root of 717719921 is about 895.3338417314. Note that the first 3 decimals are identical.

The spelling of 717719921 in words is "seven hundred seventeen million, seven hundred nineteen thousand, nine hundred twenty-one".