531139729 has 2 divisors, whose sum is σ = 531139730. Its totient is φ = 531139728.

The previous prime is 531139639. The next prime is 531139733. The reversal of 531139729 is 927931135.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 469155600 + 61984129 = 21660^2 + 7873^2 .

It is a cyclic number.

It is not a de Polignac number, because 531139729 - 2⁷ = 531139601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 531139691 and 531139700.

It is not a weakly prime, because it can be changed into another prime (531139429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265569864 + 265569865.

It is an arithmetic number, because the mean of its divisors is an integer number (265569865).

Almost surely, 2^531139729 is an apocalyptic number.

It is an amenable number.

531139729 is a deficient number, since it is larger than the sum of its proper divisors (1).

531139729 is an equidigital number, since it uses as much as digits as its factorization.

531139729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51030, while the sum is 40.

The square root of 531139729 is about 23046.4689052358. The cubic root of 531139729 is about 809.8469095425.

The spelling of 531139729 in words is "five hundred thirty-one million, one hundred thirty-nine thousand, seven hundred twenty-nine".