19501 has 2 divisors, whose sum is σ = 19502.
Its totient is φ = 19500.
The previous prime is 19489. The next prime is 19507. The reversal of 19501 is 10591.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 16900 + 2601 = 130^2 + 51^2
It is a cyclic number.
It is not a de Polignac number, because 19501 - 25 = 19469 is a prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (19507) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9750 + 9751.
It is an arithmetic number, because the mean of its divisors is an integer number (9751).
219501 is an apocalyptic number.
It is an amenable number.
19501 is a deficient number, since it is larger than the sum of its proper divisors (1).
19501 is an equidigital number, since it uses as much as digits as its factorization.
19501 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 45, while the sum is 16.
The square root of 19501 is about 139.6459809662.
The cubic root of 19501 is about 26.9165231562.
The spelling of 19501 in words is "nineteen thousand, five hundred one".