213778 has 8 divisors (see below), whose sum is σ = 324540. Its totient is φ = 105600.

The previous prime is 213751. The next prime is 213791. The reversal of 213778 is 877312.

It is a happy number.

213778 is digitally balanced in base 3, 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 157609 + 56169 = 397^2 + 237^2 .

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

It is an unprimeable 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 3 ways as a sum of consecutive naturals, for example, 423 + ... + 778.

2²¹³⁷⁷⁸ is an apocalyptic number.

213778 is a deficient number, since it is larger than the sum of its proper divisors (110762).

213778 is a wasteful number, since it uses less digits than its factorization.

213778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1292.

The product of its digits is 2352, while the sum is 28.

The square root of 213778 is about 462.3613305630. The cubic root of 213778 is about 59.7935497120.

It can be divided in two parts, 2 and 13778, that multiplied together give a square (27556 = 166²).

The spelling of 213778 in words is "two hundred thirteen thousand, seven hundred seventy-eight".