78791081477 has 2 divisors, whose sum is σ = 78791081478. Its totient is φ = 78791081476.

The previous prime is 78791081431. The next prime is 78791081491. The reversal of 78791081477 is 77418019787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57508356481 + 21282724996 = 239809^2 + 145886^2 .

It is a cyclic number.

It is not a de Polignac number, because 78791081477 - 2¹² = 78791077381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78791081407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39395540738 + 39395540739.

It is an arithmetic number, because the mean of its divisors is an integer number (39395540739).

Almost surely, 2^78791081477 is an apocalyptic number.

It is an amenable number.

78791081477 is a deficient number, since it is larger than the sum of its proper divisors (1).

78791081477 is an equidigital number, since it uses as much as digits as its factorization.

78791081477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5531904, while the sum is 59.

The spelling of 78791081477 in words is "seventy-eight billion, seven hundred ninety-one million, eighty-one thousand, four hundred seventy-seven".