91723729 has 2 divisors, whose sum is σ = 91723730. Its totient is φ = 91723728.

The previous prime is 91723651. The next prime is 91723733. The reversal of 91723729 is 92732719.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91240704 + 483025 = 9552^2 + 695^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91723729 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91723691 and 91723700.

It is not a weakly prime, because it can be changed into another prime (91723759) 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, 45861864 + 45861865.

It is an arithmetic number, because the mean of its divisors is an integer number (45861865).

Almost surely, 2^91723729 is an apocalyptic number.

It is an amenable number.

91723729 is a deficient number, since it is larger than the sum of its proper divisors (1).

91723729 is an equidigital number, since it uses as much as digits as its factorization.

91723729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 47628, while the sum is 40.

The square root of 91723729 is about 9577.2505971182. The cubic root of 91723729 is about 450.9834114675.

The spelling of 91723729 in words is "ninety-one million, seven hundred twenty-three thousand, seven hundred twenty-nine".