42328721 has 2 divisors, whose sum is σ = 42328722. Its totient is φ = 42328720.

The previous prime is 42328651. The next prime is 42328729. The reversal of 42328721 is 12782324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38887696 + 3441025 = 6236^2 + 1855^2 .

It is a cyclic number.

It is not a de Polignac number, because 42328721 - 2¹⁰ = 42327697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42328729) 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, 21164360 + 21164361.

It is an arithmetic number, because the mean of its divisors is an integer number (21164361).

Almost surely, 2^42328721 is an apocalyptic number.

It is an amenable number.

42328721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42328721 is an equidigital number, since it uses as much as digits as its factorization.

42328721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 29.

The square root of 42328721 is about 6506.0526435005. The cubic root of 42328721 is about 348.5071683076.

The spelling of 42328721 in words is "forty-two million, three hundred twenty-eight thousand, seven hundred twenty-one".