2539591861 has 2 divisors, whose sum is σ = 2539591862. Its totient is φ = 2539591860.

The previous prime is 2539591853. The next prime is 2539591871. The reversal of 2539591861 is 1681959352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2065702500 + 473889361 = 45450^2 + 21769^2 .

It is a cyclic number.

It is not a de Polignac number, because 2539591861 - 2³ = 2539591853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2539591871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1269795930 + 1269795931.

It is an arithmetic number, because the mean of its divisors is an integer number (1269795931).

Almost surely, 2^2539591861 is an apocalyptic number.

It is an amenable number.

2539591861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2539591861 is an equidigital number, since it uses as much as digits as its factorization.

2539591861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583200, while the sum is 49.

The square root of 2539591861 is about 50394.3633852041. The cubic root of 2539591861 is about 1364.3359059896.

It can be divided in two parts, 2539591 and 861, that added together give a palindrome (2540452).

The spelling of 2539591861 in words is "two billion, five hundred thirty-nine million, five hundred ninety-one thousand, eight hundred sixty-one".