2551838640681 has 16 divisors (see below), whose sum is σ = 3798085420800. Its totient is φ = 1510602154320.

The previous prime is 2551838640671. The next prime is 2551838640683. The reversal of 2551838640681 is 1860468381552.

It is not a de Polignac number, because 2551838640681 - 2⁵ = 2551838640649 is a prime.

It is a super-2 number, since 2×2551838640681² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2551838640683) 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 in 15 ways as a sum of consecutive naturals, for example, 899166531 + ... + 899169368.

It is an arithmetic number, because the mean of its divisors is an integer number (237380338800).

Almost surely, 2^{2551838640681} is an apocalyptic number.

It is an amenable number.

2551838640681 is a deficient number, since it is larger than the sum of its proper divisors (1246246780119).

2551838640681 is a wasteful number, since it uses less digits than its factorization.

2551838640681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798335956.

The product of its (nonzero) digits is 11059200, while the sum is 57.

The spelling of 2551838640681 in words is "two trillion, five hundred fifty-one billion, eight hundred thirty-eight million, six hundred forty thousand, six hundred eighty-one".