2538666761581 has 2 divisors, whose sum is σ = 2538666761582. Its totient is φ = 2538666761580.

The previous prime is 2538666761507. The next prime is 2538666761689. The reversal of 2538666761581 is 1851676668352.

It is a happy number.

2538666761581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2028513699081 + 510153062500 = 1424259^2 + 714250^2 .

It is a cyclic number.

It is not a de Polignac number, because 2538666761581 - 2²⁷ = 2538532543853 is a prime.

It is a super-2 number, since 2×2538666761581² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2538663761581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1269333380790 + 1269333380791.

It is an arithmetic number, because the mean of its divisors is an integer number (1269333380791).

Almost surely, 2^{2538666761581} is an apocalyptic number.

It is an amenable number.

2538666761581 is a deficient number, since it is larger than the sum of its proper divisors (1).

2538666761581 is an equidigital number, since it uses as much as digits as its factorization.

2538666761581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87091200, while the sum is 64.

The spelling of 2538666761581 in words is "two trillion, five hundred thirty-eight billion, six hundred sixty-six million, seven hundred sixty-one thousand, five hundred eighty-one".