2561513103805 has 8 divisors (see below), whose sum is σ = 3081558335832. Its totient is φ = 2044048742208.

The previous prime is 2561513103767. The next prime is 2561513103847. The reversal of 2561513103805 is 5083013151652.

It can be written as a sum of positive squares in 4 ways, for example, as 155871777636 + 2405641326169 = 394806^2 + 1551013^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2561513103805 - 2³¹ = 2559365620157 is a prime.

It is a super-2 number, since 2×2561513103805² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 645215422 + ... + 645219391.

It is an arithmetic number, because the mean of its divisors is an integer number (385194791979).

Almost surely, 2^{2561513103805} is an apocalyptic number.

It is an amenable number.

2561513103805 is a deficient number, since it is larger than the sum of its proper divisors (520045232027).

2561513103805 is a wasteful number, since it uses less digits than its factorization.

2561513103805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1290435215.

The product of its (nonzero) digits is 108000, while the sum is 40.

The spelling of 2561513103805 in words is "two trillion, five hundred sixty-one billion, five hundred thirteen million, one hundred three thousand, eight hundred five".