78791081491 has 2 divisors, whose sum is σ = 78791081492. Its totient is φ = 78791081490.

The previous prime is 78791081477. The next prime is 78791081561. The reversal of 78791081491 is 19418019787.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78791081491 is a prime.

It is not a weakly prime, because it can be changed into another prime (78791081431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39395540745 + 39395540746.

It is an arithmetic number, because the mean of its divisors is an integer number (39395540746).

Almost surely, 2^78791081491 is an apocalyptic number.

78791081491 is a deficient number, since it is larger than the sum of its proper divisors (1).

78791081491 is an equidigital number, since it uses as much as digits as its factorization.

78791081491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1016064, while the sum is 55.

It can be divided in two parts, 7879108 and 1491, that added together give a cube (7880599 = 199³).

The spelling of 78791081491 in words is "seventy-eight billion, seven hundred ninety-one million, eighty-one thousand, four hundred ninety-one".