68021 has 4 divisors (see below), whose sum is σ = 68544. Its totient is φ = 67500.
The previous prime is 67993. The next prime is 68023. The reversal of 68021 is 12086.
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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12086 = 2 ⋅6043.
It is a cyclic number.
It is not a de Polignac number, because 68021 - 26 = 67957 is a prime.
It is a Duffinian number.
It is a Curzon number.
It is a plaindrome in base 12.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (68023) 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, 116 + ... + 386.
It is an arithmetic number, because the mean of its divisors is an integer number (17136).
268021 is an apocalyptic number.
It is an amenable number.
68021 is a deficient number, since it is larger than the sum of its proper divisors (523).
68021 is a wasteful number, since it uses less digits than its factorization.
68021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 522.
The product of its (nonzero) digits is 96, while the sum is 17.
The square root of 68021 is about 260.8083587618. The cubic root of 68021 is about 40.8207522905.
The spelling of 68021 in words is "sixty-eight thousand, twenty-one".
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