213971 has 4 divisors (see below), whose sum is σ = 219792. Its totient is φ = 208152.

The previous prime is 213953. The next prime is 213973. The reversal of 213971 is 179312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213971 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 2855 + ... + 2928.

It is an arithmetic number, because the mean of its divisors is an integer number (54948).

2²¹³⁹⁷¹ is an apocalyptic number.

213971 is a deficient number, since it is larger than the sum of its proper divisors (5821).

213971 is an equidigital number, since it uses as much as digits as its factorization.

213971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5820.

The product of its digits is 378, while the sum is 23.

The square root of 213971 is about 462.5699947035. The cubic root of 213971 is about 59.8115382858.

The spelling of 213971 in words is "two hundred thirteen thousand, nine hundred seventy-one".