2540563681 has 2 divisors, whose sum is σ = 2540563682. Its totient is φ = 2540563680.

The previous prime is 2540563643. The next prime is 2540563703. The reversal of 2540563681 is 1863650452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2538648225 + 1915456 = 50385^2 + 1384^2 .

It is a cyclic number.

It is not a de Polignac number, because 2540563681 - 2¹³ = 2540555489 is a prime.

It is a super-2 number, since 2×2540563681² = 12908927634432539522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2540563621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1270281840 + 1270281841.

It is an arithmetic number, because the mean of its divisors is an integer number (1270281841).

Almost surely, 2^2540563681 is an apocalyptic number.

It is an amenable number.

2540563681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2540563681 is an equidigital number, since it uses as much as digits as its factorization.

2540563681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 172800, while the sum is 40.

The square root of 2540563681 is about 50404.0046127289. The cubic root of 2540563681 is about 1364.5099129303.

The spelling of 2540563681 in words is "two billion, five hundred forty million, five hundred sixty-three thousand, six hundred eighty-one".