2551656442640 has 20 divisors (see below), whose sum is σ = 5932601229324. Its totient is φ = 1020662577024.

The previous prime is 2551656442613. The next prime is 2551656442691. The reversal of 2551656442640 is 462446561552.

It can be written as a sum of positive squares in 2 ways, for example, as 1239953515024 + 1311702927616 = 1113532^2 + 1145296^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×2551656442640² (a number of 26 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15947852687 + ... + 15947852846.

Almost surely, 2^{2551656442640} is an apocalyptic number.

2551656442640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2551656442640 is an abundant number, since it is smaller than the sum of its proper divisors (3380944786684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2551656442640 is a wasteful number, since it uses less digits than its factorization.

2551656442640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31895705546 (or 31895705540 counting only the distinct ones).

The product of its (nonzero) digits is 6912000, while the sum is 50.

The spelling of 2551656442640 in words is "two trillion, five hundred fifty-one billion, six hundred fifty-six million, four hundred forty-two thousand, six hundred forty".