42775309 has 2 divisors, whose sum is σ = 42775310. Its totient is φ = 42775308.

The previous prime is 42775307. The next prime is 42775339. The reversal of 42775309 is 90357724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24950025 + 17825284 = 4995^2 + 4222^2 .

It is a cyclic number.

It is not a de Polignac number, because 42775309 - 2¹ = 42775307 is a prime.

Together with 42775307, 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 (42775303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21387654 + 21387655.

It is an arithmetic number, because the mean of its divisors is an integer number (21387655).

Almost surely, 2^42775309 is an apocalyptic number.

It is an amenable number.

42775309 is a deficient number, since it is larger than the sum of its proper divisors (1).

42775309 is an equidigital number, since it uses as much as digits as its factorization.

42775309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52920, while the sum is 37.

The square root of 42775309 is about 6540.2835565440. The cubic root of 42775309 is about 349.7285214541.

The spelling of 42775309 in words is "forty-two million, seven hundred seventy-five thousand, three hundred nine".