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242821 = 435647
BaseRepresentation
bin111011010010000101
3110100002101
4323102011
530232241
65112101
72030635
oct732205
9410071
10242821
11156487
12b8631
13866a7
14646c5
154be31
hex3b485

242821 has 4 divisors (see below), whose sum is σ = 248512. Its totient is φ = 237132.

The previous prime is 242819. The next prime is 242863. The reversal of 242821 is 128242.

242821 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 242821 - 21 = 242819 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (242521) 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, 2781 + ... + 2866.

It is an arithmetic number, because the mean of its divisors is an integer number (62128).

2242821 is an apocalyptic number.

242821 is the 285-th hex number.

It is an amenable number.

242821 is a deficient number, since it is larger than the sum of its proper divisors (5691).

242821 is an equidigital number, since it uses as much as digits as its factorization.

242821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5690.

The product of its digits is 256, while the sum is 19.

The square root of 242821 is about 492.7687084221. The cubic root of 242821 is about 62.3871884996.

The spelling of 242821 in words is "two hundred forty-two thousand, eight hundred twenty-one".

Divisors: 1 43 5647 242821