91738609 has 2 divisors, whose sum is σ = 91738610. Its totient is φ = 91738608.

The previous prime is 91738567. The next prime is 91738627. The reversal of 91738609 is 90683719.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63680400 + 28058209 = 7980^2 + 5297^2 .

It is a cyclic number.

It is not a de Polignac number, because 91738609 - 2⁷ = 91738481 is a prime.

It is not a weakly prime, because it can be changed into another prime (91738679) 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, 45869304 + 45869305.

It is an arithmetic number, because the mean of its divisors is an integer number (45869305).

Almost surely, 2^91738609 is an apocalyptic number.

It is an amenable number.

91738609 is a deficient number, since it is larger than the sum of its proper divisors (1).

91738609 is an equidigital number, since it uses as much as digits as its factorization.

91738609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 91738609 is about 9578.0274065175. The cubic root of 91738609 is about 451.0077972703.

The spelling of 91738609 in words is "ninety-one million, seven hundred thirty-eight thousand, six hundred nine".