Search a number
-
+
204021 = 3222669
BaseRepresentation
bin110001110011110101
3101100212100
4301303311
523012041
64212313
71506546
oct616365
9340770
10204021
1112a314
129a099
1371b2c
14544cd
15406b6
hex31cf5

204021 has 6 divisors (see below), whose sum is σ = 294710. Its totient is φ = 136008.

The previous prime is 204019. The next prime is 204023. The reversal of 204021 is 120402.

It is an interprime number because it is at equal distance from previous prime (204019) and next prime (204023).

It can be written as a sum of positive squares in only one way, i.e., 202500 + 1521 = 450^2 + 39^2 .

It is not a de Polignac number, because 204021 - 21 = 204019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 22669 = 204021 / (2 + 0 + 4 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 203994 and 204012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11326 + ... + 11343.

2204021 is an apocalyptic number.

It is an amenable number.

204021 is a deficient number, since it is larger than the sum of its proper divisors (90689).

204021 is a wasteful number, since it uses less digits than its factorization.

204021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22675 (or 22672 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 204021 is about 451.6868384179. The cubic root of 204021 is about 58.8696730680.

Adding to 204021 its reverse (120402), we get a palindrome (324423).

The spelling of 204021 in words is "two hundred four thousand, twenty-one", and thus it is an iban number.

Divisors: 1 3 9 22669 68007 204021