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66881 = 471423
BaseRepresentation
bin10000010101000001
310101202002
4100111001
54120011
61233345
7365663
oct202501
9111662
1066881
1146281
1232855
1324599
141a533
1514c3b
hex10541

66881 has 4 divisors (see below), whose sum is σ = 68352. Its totient is φ = 65412.

The previous prime is 66877. The next prime is 66883. The reversal of 66881 is 18866.

66881 is nontrivially palindromic in base 2 and base 4.

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: 18866 = 29433.

It is a cyclic number.

It is not a de Polignac number, because 66881 - 22 = 66877 is a prime.

It is a super-2 number, since 2×668812 = 8946136322, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 6 and base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 66881.

It is not an unprimeable number, because it can be changed into a prime (66883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 665 + ... + 758.

It is an arithmetic number, because the mean of its divisors is an integer number (17088).

266881 is an apocalyptic number.

It is an amenable number.

66881 is a deficient number, since it is larger than the sum of its proper divisors (1471).

66881 is a wasteful number, since it uses less digits than its factorization.

66881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1470.

The product of its digits is 2304, while the sum is 29.

The square root of 66881 is about 258.6136113974. The cubic root of 66881 is about 40.5914207729.

The spelling of 66881 in words is "sixty-six thousand, eight hundred eighty-one".

Divisors: 1 47 1423 66881