215281 has 4 divisors (see below), whose sum is σ = 234864. Its totient is φ = 195700.

The previous prime is 215279. The next prime is 215297. The reversal of 215281 is 182512.

215281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 215281 - 2¹ = 215279 is a prime.

It is a super-2 number, since 2×215281² = 92691817922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9775 + ... + 9796.

It is an arithmetic number, because the mean of its divisors is an integer number (58716).

2²¹⁵²⁸¹ is an apocalyptic number.

215281 is the 208-th centered decagonal number.

It is an amenable number.

215281 is a deficient number, since it is larger than the sum of its proper divisors (19583).

215281 is a wasteful number, since it uses less digits than its factorization.

215281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19582.

The product of its digits is 160, while the sum is 19.

The square root of 215281 is about 463.9838359253. The cubic root of 215281 is about 59.9333519206.

Adding to 215281 its reverse (182512), we get a palindrome (397793).

It can be divided in two parts, 215 and 281, that added together give a triangular number (496 = T₃₁).

The spelling of 215281 in words is "two hundred fifteen thousand, two hundred eighty-one".