212491 has 4 divisors (see below), whose sum is σ = 218272. Its totient is φ = 206712.

The previous prime is 212479. The next prime is 212501. The reversal of 212491 is 194212.

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 212491 - 2⁹ = 211979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212411) 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, 2835 + ... + 2908.

It is an arithmetic number, because the mean of its divisors is an integer number (54568).

2²¹²⁴⁹¹ is an apocalyptic number.

212491 is a deficient number, since it is larger than the sum of its proper divisors (5781).

212491 is an equidigital number, since it uses as much as digits as its factorization.

212491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5780.

The product of its digits is 144, while the sum is 19.

The square root of 212491 is about 460.9674608907. The cubic root of 212491 is about 59.6733171257.

It can be divided in two parts, 212 and 491, that added together give a triangular number (703 = T₃₇).

The spelling of 212491 in words is "two hundred twelve thousand, four hundred ninety-one".