91721527 has 2 divisors, whose sum is σ = 91721528. Its totient is φ = 91721526.

The previous prime is 91721521. The next prime is 91721549. The reversal of 91721527 is 72512719.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91721527 - 2¹⁵ = 91688759 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91721492 and 91721501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91721521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45860763 + 45860764.

It is an arithmetic number, because the mean of its divisors is an integer number (45860764).

Almost surely, 2^91721527 is an apocalyptic number.

91721527 is a deficient number, since it is larger than the sum of its proper divisors (1).

91721527 is an equidigital number, since it uses as much as digits as its factorization.

91721527 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8820, while the sum is 34.

The square root of 91721527 is about 9577.1356365043. The cubic root of 91721527 is about 450.9798025380.

The spelling of 91721527 in words is "ninety-one million, seven hundred twenty-one thousand, five hundred twenty-seven".