242621 has 2 divisors, whose sum is σ = 242622. Its totient is φ = 242620.

The previous prime is 242617. The next prime is 242629. The reversal of 242621 is 126242.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 235225 + 7396 = 485^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 242621 - 2² = 242617 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 242621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (242629) 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 as a sum of consecutive naturals, namely, 121310 + 121311.

It is an arithmetic number, because the mean of its divisors is an integer number (121311).

2²⁴²⁶²¹ is an apocalyptic number.

It is an amenable number.

242621 is a deficient number, since it is larger than the sum of its proper divisors (1).

242621 is an equidigital number, since it uses as much as digits as its factorization.

242621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 17.

The square root of 242621 is about 492.5657316542. The cubic root of 242621 is about 62.3700553508.

Adding to 242621 its reverse (126242), we get a palindrome (368863).

The spelling of 242621 in words is "two hundred forty-two thousand, six hundred twenty-one".