538781 has 8 divisors (see below), whose sum is σ = 585144. Its totient is φ = 494080.

The previous prime is 538777. The next prime is 538789. The reversal of 538781 is 187835.

538781 = 109² + 110² + ... + 142².

It can be written as a sum of positive squares in 4 ways, for example, as 25 + 538756 = 5^2 + 734^2 .

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 538781 - 2² = 538777 is a prime.

It is a super-2 number, since 2×538781² = 580569931922, 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 (538789) 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, 311 + ... + 1083.

It is an arithmetic number, because the mean of its divisors is an integer number (73143).

2⁵³⁸⁷⁸¹ is an apocalyptic number.

It is an amenable number.

538781 is a deficient number, since it is larger than the sum of its proper divisors (46363).

538781 is a wasteful number, since it uses less digits than its factorization.

538781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831.

The product of its digits is 6720, while the sum is 32.

The square root of 538781 is about 734.0170297752. The cubic root of 538781 is about 81.3712068677.

The spelling of 538781 in words is "five hundred thirty-eight thousand, seven hundred eighty-one".