212381 has 12 divisors (see below), whose sum is σ = 250236. Its totient is φ = 178560.

The previous prime is 212369. The next prime is 212383. The reversal of 212381 is 183212.

It can be written as a sum of positive squares in 2 ways, for example, as 96100 + 116281 = 310^2 + 341^2 .

It is not a de Polignac number, because 212381 - 2¹⁴ = 195997 is a prime.

It is a super-2 number, since 2×212381² = 90211378322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212383) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6836 + ... + 6866.

It is an arithmetic number, because the mean of its divisors is an integer number (20853).

2²¹²³⁸¹ is an apocalyptic number.

It is an amenable number.

212381 is a deficient number, since it is larger than the sum of its proper divisors (37855).

212381 is a wasteful number, since it uses less digits than its factorization.

212381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 61 counting only the distinct ones).

The product of its digits is 96, while the sum is 17.

The square root of 212381 is about 460.8481311669. The cubic root of 212381 is about 59.6630183399.

Adding to 212381 its reverse (183212), we get a palindrome (395593).

The spelling of 212381 in words is "two hundred twelve thousand, three hundred eighty-one".