212981 has 2 divisors, whose sum is σ = 212982. Its totient is φ = 212980.

The previous prime is 212969. The next prime is 212987. The reversal of 212981 is 189212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128881 + 84100 = 359^2 + 290^2 .

It is a cyclic number.

It is not a de Polignac number, because 212981 - 2⁶ = 212917 is a prime.

It is a super-2 number, since 2×212981² = 90721812722, which contains 22 as substring.

It is a Chen prime.

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

It is a plaindrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106490 + 106491.

It is an arithmetic number, because the mean of its divisors is an integer number (106491).

2²¹²⁹⁸¹ is an apocalyptic number.

It is an amenable number.

212981 is a deficient number, since it is larger than the sum of its proper divisors (1).

212981 is an equidigital number, since it uses as much as digits as its factorization.

212981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 23.

The square root of 212981 is about 461.4986457185. The cubic root of 212981 is about 59.7191504059.

The spelling of 212981 in words is "two hundred twelve thousand, nine hundred eighty-one".