91917643 has 2 divisors, whose sum is σ = 91917644. Its totient is φ = 91917642.

The previous prime is 91917607. The next prime is 91917671. The reversal of 91917643 is 34671919.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91917643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91917596 and 91917605.

It is not a weakly prime, because it can be changed into another prime (91917043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45958821 + 45958822.

It is an arithmetic number, because the mean of its divisors is an integer number (45958822).

Almost surely, 2^91917643 is an apocalyptic number.

91917643 is a deficient number, since it is larger than the sum of its proper divisors (1).

91917643 is an equidigital number, since it uses as much as digits as its factorization.

91917643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 40.

The square root of 91917643 is about 9587.3689300037. The cubic root of 91917643 is about 451.3009971958.

The spelling of 91917643 in words is "ninety-one million, nine hundred seventeen thousand, six hundred forty-three".