213855 has 16 divisors (see below), whose sum is σ = 349920. Its totient is φ = 111488.

The previous prime is 213847. The next prime is 213859. The reversal of 213855 is 558312.

It is a cyclic number.

It is not a de Polignac number, because 213855 - 2³ = 213847 is a prime.

It is a super-2 number, since 2×213855² = 91467922050, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213855.

It is not an unprimeable number, because it can be changed into a prime (213859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 661 + ... + 929.

It is an arithmetic number, because the mean of its divisors is an integer number (21870).

2²¹³⁸⁵⁵ is an apocalyptic number.

213855 is a deficient number, since it is larger than the sum of its proper divisors (136065).

213855 is a wasteful number, since it uses less digits than its factorization.

213855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330.

The product of its digits is 1200, while the sum is 24.

The square root of 213855 is about 462.4445912755. Note that the first 3 decimals coincide. The cubic root of 213855 is about 59.8007277981.

The spelling of 213855 in words is "two hundred thirteen thousand, eight hundred fifty-five".