215780 has 12 divisors (see below), whose sum is σ = 453180. Its totient is φ = 86304.

The previous prime is 215771. The next prime is 215797. The reversal of 215780 is 87512.

215780 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 87616 + 128164 = 296^2 + 358^2 .

It is a super-2 number, since 2×215780² = 93122016800, which contains 22 as substring.

It is a plaindrome in base 14.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5375 + ... + 5414.

It is an arithmetic number, because the mean of its divisors is an integer number (37765).

2²¹⁵⁷⁸⁰ is an apocalyptic number.

215780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215780 is an abundant number, since it is smaller than the sum of its proper divisors (237400).

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

215780 is a wasteful number, since it uses less digits than its factorization.

215780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10798 (or 10796 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 215780 is about 464.5212589322. The cubic root of 215780 is about 59.9796227098.

The spelling of 215780 in words is "two hundred fifteen thousand, seven hundred eighty".