42085291609 has 9 divisors (see below), whose sum is σ = 42297035391. Its totient is φ = 41874605640.

The previous prime is 42085291603. The next prime is 42085291649. The reversal of 42085291609 is 90619258024.

The square root of 42085291609 is 205147.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 25999950025 + 16085341584 = 161245^2 + 126828^2 .

It is not a de Polignac number, because 42085291609 - 2⁷ = 42085291481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42085291603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 55594459 + ... + 55595215.

It is an arithmetic number, because the mean of its divisors is an integer number (4699670599).

Almost surely, 2^42085291609 is an apocalyptic number.

42085291609 is the 205147-th square number.

42085291609 is the 102574-th centered octagonal number.

It is an amenable number.

42085291609 is a deficient number, since it is larger than the sum of its proper divisors (211743782).

42085291609 is an frugal number, since it uses more digits than its factorization.

42085291609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2056 (or 1028 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 46.

The spelling of 42085291609 in words is "forty-two billion, eighty-five million, two hundred ninety-one thousand, six hundred nine".