42565813 has 2 divisors, whose sum is σ = 42565814. Its totient is φ = 42565812.

The previous prime is 42565811. The next prime is 42565819. The reversal of 42565813 is 31856524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34374769 + 8191044 = 5863^2 + 2862^2 .

It is a cyclic number.

It is not a de Polignac number, because 42565813 - 2¹ = 42565811 is a prime.

Together with 42565811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42565811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21282906 + 21282907.

It is an arithmetic number, because the mean of its divisors is an integer number (21282907).

Almost surely, 2^42565813 is an apocalyptic number.

It is an amenable number.

42565813 is a deficient number, since it is larger than the sum of its proper divisors (1).

42565813 is an equidigital number, since it uses as much as digits as its factorization.

42565813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28800, while the sum is 34.

The square root of 42565813 is about 6524.2480792809. The cubic root of 42565813 is about 349.1566443227.

The spelling of 42565813 in words is "forty-two million, five hundred sixty-five thousand, eight hundred thirteen".