91004993 has 2 divisors, whose sum is σ = 91004994. Its totient is φ = 91004992.

The previous prime is 91004989. The next prime is 91004999. The reversal of 91004993 is 39940019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55100929 + 35904064 = 7423^2 + 5992^2 .

It is a cyclic number.

It is not a de Polignac number, because 91004993 - 2² = 91004989 is a prime.

It is not a weakly prime, because it can be changed into another prime (91004999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45502496 + 45502497.

It is an arithmetic number, because the mean of its divisors is an integer number (45502497).

Almost surely, 2^91004993 is an apocalyptic number.

It is an amenable number.

91004993 is a deficient number, since it is larger than the sum of its proper divisors (1).

91004993 is an equidigital number, since it uses as much as digits as its factorization.

91004993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 91004993 is about 9539.6537148892. The cubic root of 91004993 is about 449.8023708319.

The spelling of 91004993 in words is "ninety-one million, four thousand, nine hundred ninety-three".