91878786907 has 2 divisors, whose sum is σ = 91878786908. Its totient is φ = 91878786906.

The previous prime is 91878786893. The next prime is 91878786911. The reversal of 91878786907 is 70968787819.

It is a strong prime.

It is an emirp because it is prime and its reverse (70968787819) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91878786907 - 2¹¹ = 91878784859 is a prime.

It is a super-2 number, since 2×91878786907² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91878789907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45939393453 + 45939393454.

It is an arithmetic number, because the mean of its divisors is an integer number (45939393454).

Almost surely, 2^91878786907 is an apocalyptic number.

91878786907 is a deficient number, since it is larger than the sum of its proper divisors (1).

91878786907 is an equidigital number, since it uses as much as digits as its factorization.

91878786907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 85349376, while the sum is 70.

The spelling of 91878786907 in words is "ninety-one billion, eight hundred seventy-eight million, seven hundred eighty-six thousand, nine hundred seven".