42299821 has 2 divisors, whose sum is σ = 42299822. Its totient is φ = 42299820.

The previous prime is 42299819. The next prime is 42299827. The reversal of 42299821 is 12899224.

42299821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33802596 + 8497225 = 5814^2 + 2915^2 .

It is a cyclic number.

It is not a de Polignac number, because 42299821 - 2¹ = 42299819 is a prime.

Together with 42299819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42299827) 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, 21149910 + 21149911.

It is an arithmetic number, because the mean of its divisors is an integer number (21149911).

Almost surely, 2^42299821 is an apocalyptic number.

It is an amenable number.

42299821 is a deficient number, since it is larger than the sum of its proper divisors (1).

42299821 is an equidigital number, since it uses as much as digits as its factorization.

42299821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 37.

The square root of 42299821 is about 6503.8312554986. The cubic root of 42299821 is about 348.4278356466.

The spelling of 42299821 in words is "forty-two million, two hundred ninety-nine thousand, eight hundred twenty-one".