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72281 = 116571
BaseRepresentation
bin10001101001011001
310200011002
4101221121
54303111
61314345
7420506
oct215131
9120132
1072281
114a340
12359b5
1326b91
141c4ad
151663b
hex11a59

72281 has 4 divisors (see below), whose sum is σ = 78864. Its totient is φ = 65700.

The previous prime is 72277. The next prime is 72287. The reversal of 72281 is 18227.

72281 = T49 + T50 + ... + T81.

72281 = 762 + 772 + ... + 862.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18227 = 111657.

It is a cyclic number.

It is not a de Polignac number, because 72281 - 22 = 72277 is a prime.

It is a super-2 number, since 2×722812 = 10449085922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72287) 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, 3275 + ... + 3296.

It is an arithmetic number, because the mean of its divisors is an integer number (19716).

272281 is an apocalyptic number.

It is an amenable number.

72281 is a deficient number, since it is larger than the sum of its proper divisors (6583).

72281 is a wasteful number, since it uses less digits than its factorization.

72281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6582.

The product of its digits is 224, while the sum is 20.

The square root of 72281 is about 268.8512599933. The cubic root of 72281 is about 41.6557269057.

It can be divided in two parts, 72 and 281, that added together give a palindrome (353).

The spelling of 72281 in words is "seventy-two thousand, two hundred eighty-one".

Divisors: 1 11 6571 72281