91289993 has 2 divisors, whose sum is σ = 91289994. Its totient is φ = 91289992.

The previous prime is 91289981. The next prime is 91290037. The reversal of 91289993 is 39998219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71859529 + 19430464 = 8477^2 + 4408^2 .

It is a cyclic number.

It is not a de Polignac number, because 91289993 - 2¹² = 91285897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91289923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45644996 + 45644997.

It is an arithmetic number, because the mean of its divisors is an integer number (45644997).

Almost surely, 2^91289993 is an apocalyptic number.

It is an amenable number.

91289993 is a deficient number, since it is larger than the sum of its proper divisors (1).

91289993 is an equidigital number, since it uses as much as digits as its factorization.

91289993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 314928, while the sum is 50.

The square root of 91289993 is about 9554.5796872495. The cubic root of 91289993 is about 450.2714296626.

The spelling of 91289993 in words is "ninety-one million, two hundred eighty-nine thousand, nine hundred ninety-three".