215541 has 12 divisors (see below), whose sum is σ = 323232. Its totient is φ = 143532.

The previous prime is 215531. The next prime is 215563. The reversal of 215541 is 145512.

It is not a de Polignac number, because 215541 - 2¹⁰ = 214517 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 201 + ... + 686.

It is an arithmetic number, because the mean of its divisors is an integer number (26936).

2²¹⁵⁵⁴¹ is an apocalyptic number.

It is an amenable number.

215541 is a deficient number, since it is larger than the sum of its proper divisors (107691).

215541 is an frugal number, since it uses more digits than its factorization.

215541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902 (or 890 counting only the distinct ones).

The product of its digits is 200, while the sum is 18.

The square root of 215541 is about 464.2639335550. The cubic root of 215541 is about 59.9574698602.

The spelling of 215541 in words is "two hundred fifteen thousand, five hundred forty-one".