42843221 has 2 divisors, whose sum is σ = 42843222. Its totient is φ = 42843220.

The previous prime is 42843211. The next prime is 42843223. The reversal of 42843221 is 12234824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36663025 + 6180196 = 6055^2 + 2486^2 .

It is a cyclic number.

It is not a de Polignac number, because 42843221 - 2²² = 38648917 is a prime.

Together with 42843223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42843223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21421610 + 21421611.

It is an arithmetic number, because the mean of its divisors is an integer number (21421611).

Almost surely, 2^42843221 is an apocalyptic number.

It is an amenable number.

42843221 is a deficient number, since it is larger than the sum of its proper divisors (1).

42843221 is an equidigital number, since it uses as much as digits as its factorization.

42843221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3072, while the sum is 26.

The square root of 42843221 is about 6545.4733213115. The cubic root of 42843221 is about 349.9135051571.

The spelling of 42843221 in words is "forty-two million, eight hundred forty-three thousand, two hundred twenty-one".