5645781 has 20 divisors (see below), whose sum is σ = 8619072. Its totient is φ = 3681288.

The previous prime is 5645779. The next prime is 5645851. The reversal of 5645781 is 1875465.

5645781 is a `hidden beast` number, since 5 + 645 + 7 + 8 + 1 = 666.

It is not a de Polignac number, because 5645781 - 2¹ = 5645779 is a prime.

It is a super-2 number, since 2×5645781² = 63749686199922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5645701) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3066 + ... + 4548.

Almost surely, 2^5645781 is an apocalyptic number.

It is an amenable number.

5645781 is a deficient number, since it is larger than the sum of its proper divisors (2973291).

5645781 is a wasteful number, since it uses less digits than its factorization.

5645781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1542 (or 1533 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 5645781 is about 2376.0852257442. The cubic root of 5645781 is about 178.0634058505.

The spelling of 5645781 in words is "five million, six hundred forty-five thousand, seven hundred eighty-one".