91878960643 has 2 divisors, whose sum is σ = 91878960644. Its totient is φ = 91878960642.

The previous prime is 91878960623. The next prime is 91878960659. The reversal of 91878960643 is 34606987819.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91878960643 - 2¹⁷ = 91878829571 is a prime.

It is not a weakly prime, because it can be changed into another prime (91878960623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45939480321 + 45939480322.

It is an arithmetic number, because the mean of its divisors is an integer number (45939480322).

Almost surely, 2^91878960643 is an apocalyptic number.

91878960643 is a deficient number, since it is larger than the sum of its proper divisors (1).

91878960643 is an equidigital number, since it uses as much as digits as its factorization.

91878960643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15676416, while the sum is 61.

The spelling of 91878960643 in words is "ninety-one billion, eight hundred seventy-eight million, nine hundred sixty thousand, six hundred forty-three".