91894009 has 2 divisors, whose sum is σ = 91894010. Its totient is φ = 91894008.

The previous prime is 91894007. The next prime is 91894073. The reversal of 91894009 is 90049819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91298025 + 595984 = 9555^2 + 772^2 .

It is a cyclic number.

It is not a de Polignac number, because 91894009 - 2¹ = 91894007 is a prime.

Together with 91894007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91894007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45947004 + 45947005.

It is an arithmetic number, because the mean of its divisors is an integer number (45947005).

Almost surely, 2^91894009 is an apocalyptic number.

It is an amenable number.

91894009 is a deficient number, since it is larger than the sum of its proper divisors (1).

91894009 is an equidigital number, since it uses as much as digits as its factorization.

91894009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 91894009 is about 9586.1362915410. The cubic root of 91894009 is about 451.2623141541.

The spelling of 91894009 in words is "ninety-one million, eight hundred ninety-four thousand, nine".