91611647 has 2 divisors, whose sum is σ = 91611648. Its totient is φ = 91611646.

The previous prime is 91611643. The next prime is 91611649. The reversal of 91611647 is 74611619.

It is a strong prime.

It is an emirp because it is prime and its reverse (74611619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91611647 - 2² = 91611643 is a prime.

Together with 91611649, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91611643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45805823 + 45805824.

It is an arithmetic number, because the mean of its divisors is an integer number (45805824).

Almost surely, 2^91611647 is an apocalyptic number.

91611647 is a deficient number, since it is larger than the sum of its proper divisors (1).

91611647 is an equidigital number, since it uses as much as digits as its factorization.

91611647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 91611647 is about 9571.3973379021. The cubic root of 91611647 is about 450.7996432249.

The spelling of 91611647 in words is "ninety-one million, six hundred eleven thousand, six hundred forty-seven".