15541 has 2 divisors, whose sum is σ = 15542.
Its totient is φ = 15540.
The previous prime is 15527. The next prime is 15551. The reversal of 15541 is 14551.
Subtracting from 15541 its reverse (14551), we obtain a triangular number (990 = T44).
It can be divided in two parts, 155 and 41, that added together give a square (196 = 142).
It is a happy number.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 14641 + 900 = 121^2 + 30^2
It is an emirp because it is prime and its reverse (14551) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 15541 - 27 = 15413 is a prime.
It is a nialpdrome in base 7.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (15511) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7770 + 7771.
It is an arithmetic number, because the mean of its divisors is an integer number (7771).
215541 is an apocalyptic number.
It is an amenable number.
15541 is a deficient number, since it is larger than the sum of its proper divisors (1).
15541 is an equidigital number, since it uses as much as digits as its factorization.
15541 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 100, while the sum is 16.
The square root of 15541 is about 124.6635471980.
The cubic root of 15541 is about 24.9551194778.
The spelling of 15541 in words is "fifteen thousand, five hundred forty-one".