42072421 has 2 divisors, whose sum is σ = 42072422. Its totient is φ = 42072420.

The previous prime is 42072377. The next prime is 42072431. The reversal of 42072421 is 12427024.

It is a happy number.

42072421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42068196 + 4225 = 6486^2 + 65^2 .

It is a cyclic number.

It is not a de Polignac number, because 42072421 - 2¹⁷ = 41941349 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42072392 and 42072401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42072431) 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, 21036210 + 21036211.

It is an arithmetic number, because the mean of its divisors is an integer number (21036211).

Almost surely, 2^42072421 is an apocalyptic number.

It is an amenable number.

42072421 is a deficient number, since it is larger than the sum of its proper divisors (1).

42072421 is an equidigital number, since it uses as much as digits as its factorization.

42072421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 42072421 is about 6486.3256933336. The cubic root of 42072421 is about 347.8023412927.

Adding to 42072421 its reverse (12427024), we get a palindrome (54499445).

The spelling of 42072421 in words is "forty-two million, seventy-two thousand, four hundred twenty-one".