214821 has 6 divisors (see below), whose sum is σ = 310310. Its totient is φ = 143208.

The previous prime is 214817. The next prime is 214831. The reversal of 214821 is 128412.

214821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 202500 + 12321 = 450^2 + 111^2 .

It is not a de Polignac number, because 214821 - 2² = 214817 is a prime.

It is a super-2 number, since 2×214821² = 92296124082, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

214821 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 214794 and 214803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (214811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11926 + ... + 11943.

2²¹⁴⁸²¹ is an apocalyptic number.

It is an amenable number.

214821 is a deficient number, since it is larger than the sum of its proper divisors (95489).

214821 is a wasteful number, since it uses less digits than its factorization.

214821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23875 (or 23872 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 214821 is about 463.4878639188. The cubic root of 214821 is about 59.8906341061.

It can be divided in two parts, 214 and 821, that added together give a triangular number (1035 = T₄₅).

The spelling of 214821 in words is "two hundred fourteen thousand, eight hundred twenty-one".