91780543 has 2 divisors, whose sum is σ = 91780544. Its totient is φ = 91780542.

The previous prime is 91780537. The next prime is 91780567. The reversal of 91780543 is 34508719.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91780543 - 2¹⁷ = 91649471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91780523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45890271 + 45890272.

It is an arithmetic number, because the mean of its divisors is an integer number (45890272).

Almost surely, 2^91780543 is an apocalyptic number.

91780543 is a deficient number, since it is larger than the sum of its proper divisors (1).

91780543 is an equidigital number, since it uses as much as digits as its factorization.

91780543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 91780543 is about 9580.2162292925. The cubic root of 91780543 is about 451.0765058190.

The spelling of 91780543 in words is "ninety-one million, seven hundred eighty thousand, five hundred forty-three".