42005389 has 2 divisors, whose sum is σ = 42005390. Its totient is φ = 42005388.

The previous prime is 42005347. The next prime is 42005399. The reversal of 42005389 is 98350024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35462025 + 6543364 = 5955^2 + 2558^2 .

It is a cyclic number.

It is not a de Polignac number, because 42005389 - 2¹⁹ = 41481101 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42005389.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42005339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21002694 + 21002695.

It is an arithmetic number, because the mean of its divisors is an integer number (21002695).

Almost surely, 2^42005389 is an apocalyptic number.

It is an amenable number.

42005389 is a deficient number, since it is larger than the sum of its proper divisors (1).

42005389 is an equidigital number, since it uses as much as digits as its factorization.

42005389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 42005389 is about 6481.1564554484. The cubic root of 42005389 is about 347.6175307636.

The spelling of 42005389 in words is "forty-two million, five thousand, three hundred eighty-nine".