2561512878838 has 16 divisors (see below), whose sum is σ = 3847988559024. Its totient is φ = 1278850613760.

The previous prime is 2561512878829. The next prime is 2561512878853. The reversal of 2561512878838 is 8388782151652.

It is a super-2 number, since 2×2561512878838² (a number of 26 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2561512878838.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 8770681 + ... + 9058027.

It is an arithmetic number, because the mean of its divisors is an integer number (240499284939).

Almost surely, 2^{2561512878838} is an apocalyptic number.

2561512878838 is a deficient number, since it is larger than the sum of its proper divisors (1286475680186).

2561512878838 is a wasteful number, since it uses less digits than its factorization.

2561512878838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293967.

The product of its digits is 51609600, while the sum is 64.

The spelling of 2561512878838 in words is "two trillion, five hundred sixty-one billion, five hundred twelve million, eight hundred seventy-eight thousand, eight hundred thirty-eight".