2643648781 has 8 divisors (see below), whose sum is σ = 2655100800. Its totient is φ = 2632222320.

The previous prime is 2643648757. The next prime is 2643648793. The reversal of 2643648781 is 1878463462.

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 2643648781 - 2⁹ = 2643648269 is a prime.

It is a super-2 number, since 2×2643648781² = 13977757754565571922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2643648701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 217536 + ... + 229366.

It is an arithmetic number, because the mean of its divisors is an integer number (331887600).

Almost surely, 2^2643648781 is an apocalyptic number.

It is an amenable number.

2643648781 is a deficient number, since it is larger than the sum of its proper divisors (11452019).

2643648781 is a wasteful number, since it uses less digits than its factorization.

2643648781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12779.

The product of its digits is 1548288, while the sum is 49.

The square root of 2643648781 is about 51416.4252063482. The cubic root of 2643648781 is about 1382.7210857346.

The spelling of 2643648781 in words is "two billion, six hundred forty-three million, six hundred forty-eight thousand, seven hundred eighty-one".