1538779140881 has 2 divisors, whose sum is σ = 1538779140882. Its totient is φ = 1538779140880.

The previous prime is 1538779140841. The next prime is 1538779140889. The reversal of 1538779140881 is 1880419778351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1424072289025 + 114706851856 = 1193345^2 + 338684^2 .

It is a cyclic number.

It is not a de Polignac number, because 1538779140881 - 2²⁶ = 1538712032017 is a prime.

It is a super-2 number, since 2×1538779140881² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1538779140889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 769389570440 + 769389570441.

It is an arithmetic number, because the mean of its divisors is an integer number (769389570441).

Almost surely, 2^{1538779140881} is an apocalyptic number.

It is an amenable number.

1538779140881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1538779140881 is an equidigital number, since it uses as much as digits as its factorization.

1538779140881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13547520, while the sum is 62.

The spelling of 1538779140881 in words is "one trillion, five hundred thirty-eight billion, seven hundred seventy-nine million, one hundred forty thousand, eight hundred eighty-one".