215705 has 8 divisors (see below), whose sum is σ = 295872. Its totient is φ = 147888.

The previous prime is 215693. The next prime is 215723. The reversal of 215705 is 507512.

215705 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 215705 - 2⁴ = 215689 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3047 + ... + 3116.

It is an arithmetic number, because the mean of its divisors is an integer number (36984).

2²¹⁵⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

215705 is a deficient number, since it is larger than the sum of its proper divisors (80167).

215705 is an equidigital number, since it uses as much as digits as its factorization.

215705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6175.

The product of its (nonzero) digits is 350, while the sum is 20.

The square root of 215705 is about 464.4405236411. The cubic root of 215705 is about 59.9726727408.

It can be divided in two parts, 21 and 5705, that multiplied together give a triangular number (119805 = T₄₈₉).

The spelling of 215705 in words is "two hundred fifteen thousand, seven hundred five".