91660643 has 2 divisors, whose sum is σ = 91660644. Its totient is φ = 91660642.

The previous prime is 91660567. The next prime is 91660663. The reversal of 91660643 is 34606619.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91660643 - 2¹⁸ = 91398499 is a prime.

It is not a weakly prime, because it can be changed into another prime (91660663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45830321 + 45830322.

It is an arithmetic number, because the mean of its divisors is an integer number (45830322).

Almost surely, 2^91660643 is an apocalyptic number.

91660643 is a deficient number, since it is larger than the sum of its proper divisors (1).

91660643 is an equidigital number, since it uses as much as digits as its factorization.

91660643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 91660643 is about 9573.9564966632. The cubic root of 91660643 is about 450.8799948818.

The spelling of 91660643 in words is "ninety-one million, six hundred sixty thousand, six hundred forty-three".