73721 has 2 divisors, whose sum is σ = 73722.
Its totient is φ = 73720.
The previous prime is 73709. The next prime is 73727. The reversal of 73721 is 12737.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 55225 + 18496 = 235^2 + 136^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-73721 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 73693 and 73702.
It is not a weakly prime, because it can be changed into another prime (73727) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36860 + 36861.
It is an arithmetic number, because the mean of its divisors is an integer number (36861).
273721 is an apocalyptic number.
It is an amenable number.
73721 is a deficient number, since it is larger than the sum of its proper divisors (1).
73721 is an equidigital number, since it uses as much as digits as its factorization.
73721 is an evil number, because the sum of its binary digits is even.
The product of its digits is 294, while the sum is 20.
The square root of 73721 is about 271.5161137023.
The cubic root of 73721 is about 41.9305352117.
The spelling of 73721 in words is "seventy-three thousand, seven hundred twenty-one", and thus it is an iban number.