213780 has 48 divisors (see below), whose sum is σ = 685440. Its totient is φ = 48768.

The previous prime is 213751. The next prime is 213791. The reversal of 213780 is 87312.

213780 is digitally balanced in base 3, 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 (21).

It is a congruent number.

It is an unprimeable number.

213780 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166 + ... + 674.

It is an arithmetic number, because the mean of its divisors is an integer number (14280).

2²¹³⁷⁸⁰ is an apocalyptic number.

213780 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 213780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342720).

213780 is an abundant number, since it is smaller than the sum of its proper divisors (471660).

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

213780 is a wasteful number, since it uses less digits than its factorization.

213780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528 (or 526 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 213780 is about 462.3634933686. The cubic root of 213780 is about 59.7937361776.

Subtracting from 213780 its product of nonzero digits (336), we obtain a square (213444 = 462²).

The spelling of 213780 in words is "two hundred thirteen thousand, seven hundred eighty".