38921 has 2 divisors, whose sum is σ = 38922.
Its totient is φ = 38920.
The previous prime is 38917. The next prime is 38923. The reversal of 38921 is 12983.
It can be divided in two parts, 38 and 921, that added together give a palindrome (959).
38921 = 1392 + 1402.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 19600 + 19321 = 140^2 + 139^2
It is an emirp because it is prime and its reverse (12983) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 38921 - 22 = 38917 is a prime.
Together with 38923, it forms a pair of twin primes.
It is a Chen prime.
It is an alternating number because its digits alternate between odd and even.
It is not a weakly prime, because it can be changed into another prime (38923) 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 as a sum of consecutive naturals, namely, 19460 + 19461.
It is an arithmetic number, because the mean of its divisors is an integer number (19461).
238921 is an apocalyptic number.
38921 is the 140-th centered square number.
It is an amenable number.
38921 is a deficient number, since it is larger than the sum of its proper divisors (1).
38921 is an equidigital number, since it uses as much as digits as its factorization.
38921 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 432, while the sum is 23.
The square root of 38921 is about 197.2840591634.
The cubic root of 38921 is about 33.8892010283.
The spelling of 38921 in words is "thirty-eight thousand, nine hundred twenty-one".