42509729 has 2 divisors, whose sum is σ = 42509730. Its totient is φ = 42509728.

The previous prime is 42509717. The next prime is 42509767. The reversal of 42509729 is 92790524.

It is an a-pointer prime, because the next prime (42509767) can be obtained adding 42509729 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28462225 + 14047504 = 5335^2 + 3748^2 .

It is a cyclic number.

It is not a de Polignac number, because 42509729 - 2⁸ = 42509473 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 42509692 and 42509701.

It is not a weakly prime, because it can be changed into another prime (42509429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21254864 + 21254865.

It is an arithmetic number, because the mean of its divisors is an integer number (21254865).

Almost surely, 2^42509729 is an apocalyptic number.

It is an amenable number.

42509729 is a deficient number, since it is larger than the sum of its proper divisors (1).

42509729 is an equidigital number, since it uses as much as digits as its factorization.

42509729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 42509729 is about 6519.9485427417. The cubic root of 42509729 is about 349.0032292813.

The spelling of 42509729 in words is "forty-two million, five hundred nine thousand, seven hundred twenty-nine".