42521389 has 2 divisors, whose sum is σ = 42521390. Its totient is φ = 42521388.

The previous prime is 42521383. The next prime is 42521419. The reversal of 42521389 is 98312524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29975625 + 12545764 = 5475^2 + 3542^2 .

It is a cyclic number.

It is not a de Polignac number, because 42521389 - 2⁵ = 42521357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42521383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21260694 + 21260695.

It is an arithmetic number, because the mean of its divisors is an integer number (21260695).

Almost surely, 2^42521389 is an apocalyptic number.

It is an amenable number.

42521389 is a deficient number, since it is larger than the sum of its proper divisors (1).

42521389 is an equidigital number, since it uses as much as digits as its factorization.

42521389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 34.

The square root of 42521389 is about 6520.8426602702. The cubic root of 42521389 is about 349.0351357471.

The spelling of 42521389 in words is "forty-two million, five hundred twenty-one thousand, three hundred eighty-nine".