215660 has 24 divisors (see below), whose sum is σ = 465696. Its totient is φ = 83840.

The previous prime is 215659. The next prime is 215681. The reversal of 215660 is 66512.

215660 = T₅₃ + T₅₄ + ... + T₁₁₂.

215660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 689 + ... + 951.

It is an arithmetic number, because the mean of its divisors is an integer number (19404).

2²¹⁵⁶⁶⁰ is an apocalyptic number.

215660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (232848).

215660 is an abundant number, since it is smaller than the sum of its proper divisors (250036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

215660 is a wasteful number, since it uses less digits than its factorization.

215660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 215660 is about 464.3920757291. The cubic root of 215660 is about 59.9685019860.

The spelling of 215660 in words is "two hundred fifteen thousand, six hundred sixty".