5781581 has 8 divisors (see below), whose sum is σ = 6592824. Its totient is φ = 5022720.

The previous prime is 5781571. The next prime is 5781599. The reversal of 5781581 is 1851875.

5781581 = 459² + 460² + ... + 484².

It can be written as a sum of positive squares in 4 ways, for example, as 259081 + 5522500 = 509^2 + 2350^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5781581 is a prime.

It is a super-2 number, since 2×5781581² = 66853357719122, 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 (5781541) 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, 12860 + ... + 13301.

It is an arithmetic number, because the mean of its divisors is an integer number (824103).

Almost surely, 2^5781581 is an apocalyptic number.

It is an amenable number.

5781581 is a deficient number, since it is larger than the sum of its proper divisors (811243).

5781581 is a wasteful number, since it uses less digits than its factorization.

5781581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26191.

The product of its digits is 11200, while the sum is 35.

The square root of 5781581 is about 2404.4918382062. The cubic root of 5781581 is about 179.4797839861.

The spelling of 5781581 in words is "five million, seven hundred eighty-one thousand, five hundred eighty-one".