278213 has 4 divisors (see below), whose sum is σ = 299628. Its totient is φ = 256800.

The previous prime is 278209. The next prime is 278219. The reversal of 278213 is 312872.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 49729 + 228484 = 223^2 + 478^2 .

It is a cyclic number.

It is not a de Polignac number, because 278213 - 2² = 278209 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10688 + ... + 10713.

It is an arithmetic number, because the mean of its divisors is an integer number (74907).

2²⁷⁸²¹³ is an apocalyptic number.

It is an amenable number.

278213 is a deficient number, since it is larger than the sum of its proper divisors (21415).

278213 is a wasteful number, since it uses less digits than its factorization.

278213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21414.

The product of its digits is 672, while the sum is 23.

The square root of 278213 is about 527.4590031462. The cubic root of 278213 is about 65.2818529857.

The spelling of 278213 in words is "two hundred seventy-eight thousand, two hundred thirteen".