215890 has 8 divisors (see below), whose sum is σ = 388620. Its totient is φ = 86352.

The previous prime is 215863. The next prime is 215893. The reversal of 215890 is 98512.

215890 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 214369 + 1521 = 463^2 + 39^2 .

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

It is not an unprimeable number, because it can be changed into a prime (215893) by changing a digit.

215890 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10785 + ... + 10804.

2²¹⁵⁸⁹⁰ is an apocalyptic number.

215890 is a deficient number, since it is larger than the sum of its proper divisors (172730).

215890 is a wasteful number, since it uses less digits than its factorization.

215890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21596.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 215890 is about 464.6396453167. The cubic root of 215890 is about 59.9898130854.

The spelling of 215890 in words is "two hundred fifteen thousand, eight hundred ninety".