64981 has 4 divisors (see below), whose sum is σ = 74272. Its totient is φ = 55692.
The previous prime is 64969. The next prime is 64997. The reversal of 64981 is 18946.
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: 18946 = 2 ⋅9473.
It is not a de Polignac number, because 64981 - 27 = 64853 is a prime.
It is a super-2 number, since 2×649812 = 8445060722, which contains 22 as substring.
It is a pancake number, because a pancake can be divided into 64981 parts by 360 straight cuts.
It is a Duffinian number.
It is a nialpdrome in base 16.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (64901) 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, 4635 + ... + 4648.
It is an arithmetic number, because the mean of its divisors is an integer number (18568).
264981 is an apocalyptic number.
It is an amenable number.
64981 is a deficient number, since it is larger than the sum of its proper divisors (9291).
64981 is an equidigital number, since it uses as much as digits as its factorization.
64981 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 9290.
The product of its digits is 1728, while the sum is 28.
The square root of 64981 is about 254.9137108906. The cubic root of 64981 is about 40.2033395739.
The spelling of 64981 in words is "sixty-four thousand, nine hundred eighty-one".
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