42505729 has 16 divisors (see below), whose sum is σ = 51608448. Its totient is φ = 34175232.

The previous prime is 42505703. The next prime is 42505733. The reversal of 42505729 is 92750524.

It is not a de Polignac number, because 42505729 - 2⁷ = 42505601 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42505694 and 42505703.

It is not an unprimeable number, because it can be changed into a prime (42505759) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64767 + ... + 65419.

It is an arithmetic number, because the mean of its divisors is an integer number (3225528).

Almost surely, 2^42505729 is an apocalyptic number.

It is an amenable number.

42505729 is a deficient number, since it is larger than the sum of its proper divisors (9102719).

42505729 is a wasteful number, since it uses less digits than its factorization.

42505729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1224.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 42505729 is about 6519.6417846382. The cubic root of 42505729 is about 348.9922823229.

It can be divided in two parts, 42505 and 729, that added together give a palindrome (43234).

The spelling of 42505729 in words is "forty-two million, five hundred five thousand, seven hundred twenty-nine".