2551681680261 has 16 divisors (see below), whose sum is σ = 3890161680384. Its totient is φ = 1457397004464.

The previous prime is 2551681680211. The next prime is 2551681680287. The reversal of 2551681680261 is 1620861861552.

It is not a de Polignac number, because 2551681680261 - 2¹⁷ = 2551681549189 is a prime.

It is a super-2 number, since 2×2551681680261² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2551681680211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29406181 + ... + 29492826.

It is an arithmetic number, because the mean of its divisors is an integer number (243135105024).

Almost surely, 2^{2551681680261} is an apocalyptic number.

2551681680261 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2551681680261 is a deficient number, since it is larger than the sum of its proper divisors (1338480000123).

2551681680261 is a wasteful number, since it uses less digits than its factorization.

2551681680261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58901080.

The product of its (nonzero) digits is 1382400, while the sum is 51.

The spelling of 2551681680261 in words is "two trillion, five hundred fifty-one billion, six hundred eighty-one million, six hundred eighty thousand, two hundred sixty-one".