91739521 has 2 divisors, whose sum is σ = 91739522. Its totient is φ = 91739520.

The previous prime is 91739519. The next prime is 91739533. The reversal of 91739521 is 12593719.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79566400 + 12173121 = 8920^2 + 3489^2 .

It is a cyclic number.

It is not a de Polignac number, because 91739521 - 2¹ = 91739519 is a prime.

It is a super-2 number, since 2×91739521² = 16832279426618882, which contains 22 as substring.

Together with 91739519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91739321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45869760 + 45869761.

It is an arithmetic number, because the mean of its divisors is an integer number (45869761).

Almost surely, 2^91739521 is an apocalyptic number.

It is an amenable number.

91739521 is a deficient number, since it is larger than the sum of its proper divisors (1).

91739521 is an equidigital number, since it uses as much as digits as its factorization.

91739521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17010, while the sum is 37.

The square root of 91739521 is about 9578.0750153671. The cubic root of 91739521 is about 451.0092917983.

The spelling of 91739521 in words is "ninety-one million, seven hundred thirty-nine thousand, five hundred twenty-one".