5645738781 has 24 divisors (see below), whose sum is σ = 8197716800. Its totient is φ = 3744138816.

The previous prime is 5645738759. The next prime is 5645738801. The reversal of 5645738781 is 1878375465.

It is a happy number.

5645738781 is a `hidden beast` number, since 5 + 64 + 573 + 8 + 7 + 8 + 1 = 666.

It is not a de Polignac number, because 5645738781 - 2¹³ = 5645730589 is a prime.

It is a super-2 number, since 2×5645738781² = 63748732766574731922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5645738741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1850145 + ... + 1853193.

Almost surely, 2^5645738781 is an apocalyptic number.

It is an amenable number.

5645738781 is a deficient number, since it is larger than the sum of its proper divisors (2551978019).

5645738781 is a wasteful number, since it uses less digits than its factorization.

5645738781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4065 (or 4062 counting only the distinct ones).

The product of its digits is 5644800, while the sum is 54.

The square root of 5645738781 is about 75138.1313382227. The cubic root of 5645738781 is about 1780.6296199828.

The spelling of 5645738781 in words is "five billion, six hundred forty-five million, seven hundred thirty-eight thousand, seven hundred eighty-one".