89491391987 has 2 divisors, whose sum is σ = 89491391988. Its totient is φ = 89491391986.

The previous prime is 89491391963. The next prime is 89491392013. The reversal of 89491391987 is 78919319498.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 89491391987 - 2¹² = 89491387891 is a prime.

It is not a weakly prime, because it can be changed into another prime (89491396987) 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, 44745695993 + 44745695994.

It is an arithmetic number, because the mean of its divisors is an integer number (44745695994).

Almost surely, 2^89491391987 is an apocalyptic number.

89491391987 is a deficient number, since it is larger than the sum of its proper divisors (1).

89491391987 is an equidigital number, since it uses as much as digits as its factorization.

89491391987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35271936, while the sum is 68.

The spelling of 89491391987 in words is "eighty-nine billion, four hundred ninety-one million, three hundred ninety-one thousand, nine hundred eighty-seven".