252781 has 4 divisors (see below), whose sum is σ = 255132. Its totient is φ = 250432.

The previous prime is 252779. The next prime is 252817. The reversal of 252781 is 187252.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 84681 + 168100 = 291^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 252781 - 2¹ = 252779 is a prime.

It is a super-2 number, since 2×252781² = 127796467922, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (252731) 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 3 ways as a sum of consecutive naturals, for example, 1006 + ... + 1231.

It is an arithmetic number, because the mean of its divisors is an integer number (63783).

2²⁵²⁷⁸¹ is an apocalyptic number.

It is an amenable number.

252781 is a deficient number, since it is larger than the sum of its proper divisors (2351).

252781 is a wasteful number, since it uses less digits than its factorization.

252781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2350.

The product of its digits is 1120, while the sum is 25.

The square root of 252781 is about 502.7733087585. The cubic root of 252781 is about 63.2287810215.

The spelling of 252781 in words is "two hundred fifty-two thousand, seven hundred eighty-one".