42010721 has 2 divisors, whose sum is σ = 42010722. Its totient is φ = 42010720.

The previous prime is 42010693. The next prime is 42010739. The reversal of 42010721 is 12701024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35046400 + 6964321 = 5920^2 + 2639^2 .

It is a cyclic number.

It is not a de Polignac number, because 42010721 - 2¹⁰ = 42009697 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 42010721.

It is not a weakly prime, because it can be changed into another prime (42010741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21005360 + 21005361.

It is an arithmetic number, because the mean of its divisors is an integer number (21005361).

Almost surely, 2^42010721 is an apocalyptic number.

It is an amenable number.

42010721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42010721 is an equidigital number, since it uses as much as digits as its factorization.

42010721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 42010721 is about 6481.5677887375. The cubic root of 42010721 is about 347.6322385452.

Adding to 42010721 its reverse (12701024), we get a palindrome (54711745).

The spelling of 42010721 in words is "forty-two million, ten thousand, seven hundred twenty-one".