15781777320427 has 2 divisors, whose sum is σ = 15781777320428. Its totient is φ = 15781777320426.

The previous prime is 15781777320389. The next prime is 15781777320433. The reversal of 15781777320427 is 72402377718751.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15781777320427 - 2¹¹ = 15781777318379 is a prime.

It is not a weakly prime, because it can be changed into another prime (15781777320437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7890888660213 + 7890888660214.

It is an arithmetic number, because the mean of its divisors is an integer number (7890888660214).

Almost surely, 2^{15781777320427} is an apocalyptic number.

15781777320427 is a deficient number, since it is larger than the sum of its proper divisors (1).

15781777320427 is an equidigital number, since it uses as much as digits as its factorization.

15781777320427 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32269440, while the sum is 61.

The spelling of 15781777320427 in words is "fifteen trillion, seven hundred eighty-one billion, seven hundred seventy-seven million, three hundred twenty thousand, four hundred twenty-seven".