42552721 has 2 divisors, whose sum is σ = 42552722. Its totient is φ = 42552720.

The previous prime is 42552707. The next prime is 42552743. The reversal of 42552721 is 12725524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33189121 + 9363600 = 5761^2 + 3060^2 .

It is a cyclic number.

It is not a de Polignac number, because 42552721 - 2¹⁹ = 42028433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42552721.

It is not a weakly prime, because it can be changed into another prime (42552791) 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 as a sum of consecutive naturals, namely, 21276360 + 21276361.

It is an arithmetic number, because the mean of its divisors is an integer number (21276361).

Almost surely, 2^42552721 is an apocalyptic number.

It is an amenable number.

42552721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42552721 is an equidigital number, since it uses as much as digits as its factorization.

42552721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5600, while the sum is 28.

The square root of 42552721 is about 6523.2446681080. The cubic root of 42552721 is about 349.1208438591.

The spelling of 42552721 in words is "forty-two million, five hundred fifty-two thousand, seven hundred twenty-one".