538239779681 has 2 divisors, whose sum is σ = 538239779682. Its totient is φ = 538239779680.

The previous prime is 538239779663. The next prime is 538239779807. The reversal of 538239779681 is 186977932835.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 322386619681 + 215853160000 = 567791^2 + 464600^2 .

It is a cyclic number.

It is not a de Polignac number, because 538239779681 - 2³⁰ = 537166037857 is a prime.

It is a super-2 number, since 2×538239779681² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (538239779641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 269119889840 + 269119889841.

It is an arithmetic number, because the mean of its divisors is an integer number (269119889841).

Almost surely, 2^538239779681 is an apocalyptic number.

It is an amenable number.

538239779681 is a deficient number, since it is larger than the sum of its proper divisors (1).

538239779681 is an equidigital number, since it uses as much as digits as its factorization.

538239779681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 137168640, while the sum is 68.

The spelling of 538239779681 in words is "five hundred thirty-eight billion, two hundred thirty-nine million, seven hundred seventy-nine thousand, six hundred eighty-one".