213851 has 4 divisors (see below), whose sum is σ = 233304. Its totient is φ = 194400.

The previous prime is 213847. The next prime is 213859. The reversal of 213851 is 158312.

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

It is a cyclic number.

It is not a de Polignac number, because 213851 - 2² = 213847 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213851.

It is not an unprimeable number, because it can be changed into a prime (213859) 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, 9710 + ... + 9731.

It is an arithmetic number, because the mean of its divisors is an integer number (58326).

2²¹³⁸⁵¹ is an apocalyptic number.

213851 is a deficient number, since it is larger than the sum of its proper divisors (19453).

213851 is a wasteful number, since it uses less digits than its factorization.

213851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19452.

The product of its digits is 240, while the sum is 20.

The square root of 213851 is about 462.4402664129. The cubic root of 213851 is about 59.8003549529.

The spelling of 213851 in words is "two hundred thirteen thousand, eight hundred fifty-one".