2581236781247 has 4 divisors (see below), whose sum is σ = 2581240242000. Its totient is φ = 2581233320496.

The previous prime is 2581236781237. The next prime is 2581236781261. The reversal of 2581236781247 is 7421876321852.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2581236781247 - 2⁴ = 2581236781231 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2581236781192 and 2581236781201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581236781237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98747 + ... + 2274252.

It is an arithmetic number, because the mean of its divisors is an integer number (645310060500).

Almost surely, 2^{2581236781247} is an apocalyptic number.

2581236781247 is a deficient number, since it is larger than the sum of its proper divisors (3460753).

2581236781247 is a wasteful number, since it uses less digits than its factorization.

2581236781247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3460752.

The product of its digits is 9031680, while the sum is 56.

The spelling of 2581236781247 in words is "two trillion, five hundred eighty-one billion, two hundred thirty-six million, seven hundred eighty-one thousand, two hundred forty-seven".