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47821 = 172997
BaseRepresentation
bin1011101011001101
32102121011
423223031
53012241
61005221
7256264
oct135315
972534
1047821
1132a24
1223811
13189c7
14135db
15e281
hexbacd

47821 has 8 divisors (see below), whose sum is σ = 52920. Its totient is φ = 43008.

The previous prime is 47819. The next prime is 47837. The reversal of 47821 is 12874.

47821 = T8 + T9 + ... + T65.

It can be written as a sum of positive squares in 4 ways, for example, as 12100 + 35721 = 110^2 + 189^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 47821 - 21 = 47819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 47792 and 47801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 445 + ... + 541.

It is an arithmetic number, because the mean of its divisors is an integer number (6615).

247821 is an apocalyptic number.

It is an amenable number.

47821 is a deficient number, since it is larger than the sum of its proper divisors (5099).

47821 is a wasteful number, since it uses less digits than its factorization.

47821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143.

The product of its digits is 448, while the sum is 22.

The square root of 47821 is about 218.6801316992. The cubic root of 47821 is about 36.2971799472.

It can be divided in two parts, 47 and 821, that added together give a palindrome (868).

The spelling of 47821 in words is "forty-seven thousand, eight hundred twenty-one".

Divisors: 1 17 29 97 493 1649 2813 47821