213978 has 16 divisors (see below), whose sum is σ = 450720. Its totient is φ = 67536.

The previous prime is 213977. The next prime is 213989. The reversal of 213978 is 879312.

It is a happy number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213978.

It is not an unprimeable number, because it can be changed into a prime (213973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 825 + ... + 1052.

It is an arithmetic number, because the mean of its divisors is an integer number (28170).

2²¹³⁹⁷⁸ is an apocalyptic number.

213978 is an abundant number, since it is smaller than the sum of its proper divisors (236742).

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

213978 is a wasteful number, since it uses less digits than its factorization.

213978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1901.

The product of its digits is 3024, while the sum is 30.

The square root of 213978 is about 462.5775610641. The cubic root of 213978 is about 59.8121905178.

It can be divided in two parts, 21 and 3978, that multiplied together give a palindrome (83538).

The spelling of 213978 in words is "two hundred thirteen thousand, nine hundred seventy-eight".