42439708081 has 3 divisors (see below), whose sum is σ = 42439914091. Its totient is φ = 42439502072.

The previous prime is 42439708079. The next prime is 42439708121. The reversal of 42439708081 is 18080793424.

The square root of 42439708081 is 206009.

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

42439708081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 11926605681 + 30513102400 = 109209^2 + 174680^2 .

It is not a de Polignac number, because 42439708081 - 2¹ = 42439708079 is a prime.

It is a super-5 number, since 5×42439708081⁵ (a number of 54 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42439708001) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 103005 + ... + 309013.

Almost surely, 2^42439708081 is an apocalyptic number.

42439708081 is the 206009-th square number.

42439708081 is the 103005-th centered octagonal number.

It is an amenable number.

42439708081 is a deficient number, since it is larger than the sum of its proper divisors (206010).

42439708081 is an frugal number, since it uses more digits than its factorization.

42439708081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412018 (or 206009 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 46.

The spelling of 42439708081 in words is "forty-two billion, four hundred thirty-nine million, seven hundred eight thousand, eighty-one".