42321221 has 4 divisors (see below), whose sum is σ = 42379692. Its totient is φ = 42262752.

The previous prime is 42321203. The next prime is 42321241. The reversal of 42321221 is 12212324.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25140196 + 17181025 = 5014^2 + 4145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42321221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42321221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42321241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28136 + ... + 29601.

It is an arithmetic number, because the mean of its divisors is an integer number (10594923).

Almost surely, 2^42321221 is an apocalyptic number.

It is an amenable number.

42321221 is a deficient number, since it is larger than the sum of its proper divisors (58471).

42321221 is an equidigital number, since it uses as much as digits as its factorization.

42321221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58470.

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

The square root of 42321221 is about 6505.4762316067. The cubic root of 42321221 is about 348.4865837172.

Adding to 42321221 its reverse (12212324), we get a palindrome (54533545).

The spelling of 42321221 in words is "forty-two million, three hundred twenty-one thousand, two hundred twenty-one".