2581651397609 has 2 divisors, whose sum is σ = 2581651397610. Its totient is φ = 2581651397608.

The previous prime is 2581651397579. The next prime is 2581651397683. The reversal of 2581651397609 is 9067931561852.

2581651397609 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., 2578824880384 + 2826517225 = 1605872^2 + 53165^2 .

It is a cyclic number.

It is not a de Polignac number, because 2581651397609 - 2¹² = 2581651393513 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (2581651399609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1290825698804 + 1290825698805.

It is an arithmetic number, because the mean of its divisors is an integer number (1290825698805).

Almost surely, 2^{2581651397609} is an apocalyptic number.

It is an amenable number.

2581651397609 is a deficient number, since it is larger than the sum of its proper divisors (1).

2581651397609 is an equidigital number, since it uses as much as digits as its factorization.

2581651397609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24494400, while the sum is 62.

The spelling of 2581651397609 in words is "two trillion, five hundred eighty-one billion, six hundred fifty-one million, three hundred ninety-seven thousand, six hundred nine".