91505647 has 2 divisors, whose sum is σ = 91505648. Its totient is φ = 91505646.

The previous prime is 91505641. The next prime is 91505681. The reversal of 91505647 is 74650519.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91505647 - 2³ = 91505639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91505641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45752823 + 45752824.

It is an arithmetic number, because the mean of its divisors is an integer number (45752824).

Almost surely, 2^91505647 is an apocalyptic number.

91505647 is a deficient number, since it is larger than the sum of its proper divisors (1).

91505647 is an equidigital number, since it uses as much as digits as its factorization.

91505647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 91505647 is about 9565.8584037189. The cubic root of 91505647 is about 450.6257089945.

The spelling of 91505647 in words is "ninety-one million, five hundred five thousand, six hundred forty-seven".