212639 has 8 divisors (see below), whose sum is σ = 249888. Its totient is φ = 177120.

The previous prime is 212633. The next prime is 212651. The reversal of 212639 is 936212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212639 - 2⁸ = 212383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152 + ... + 669.

It is an arithmetic number, because the mean of its divisors is an integer number (31236).

2²¹²⁶³⁹ is an apocalyptic number.

212639 is a deficient number, since it is larger than the sum of its proper divisors (37249).

212639 is an equidigital number, since it uses as much as digits as its factorization.

212639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865.

The product of its digits is 648, while the sum is 23.

The square root of 212639 is about 461.1279648861. The cubic root of 212639 is about 59.6871680674.

The spelling of 212639 in words is "two hundred twelve thousand, six hundred thirty-nine".