1542439446781 has 2 divisors, whose sum is σ = 1542439446782. Its totient is φ = 1542439446780.

The previous prime is 1542439446731. The next prime is 1542439446853. The reversal of 1542439446781 is 1876449342451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1395623263225 + 146816183556 = 1181365^2 + 383166^2 .

It is an emirp because it is prime and its reverse (1876449342451) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1542439446781 is a prime.

It is a super-2 number, since 2×1542439446781² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1542439446731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 771219723390 + 771219723391.

It is an arithmetic number, because the mean of its divisors is an integer number (771219723391).

Almost surely, 2^{1542439446781} is an apocalyptic number.

It is an amenable number.

1542439446781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1542439446781 is an equidigital number, since it uses as much as digits as its factorization.

1542439446781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23224320, while the sum is 58.

The spelling of 1542439446781 in words is "one trillion, five hundred forty-two billion, four hundred thirty-nine million, four hundred forty-six thousand, seven hundred eighty-one".