42805085861 has 4 divisors (see below), whose sum is σ = 42832650252. Its totient is φ = 42777521472.

The previous prime is 42805085849. The next prime is 42805085899. The reversal of 42805085861 is 16858050824.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2715035236 + 40090050625 = 52106^2 + 200225^2 .

It is a cyclic number.

It is not a de Polignac number, because 42805085861 - 2¹⁰ = 42805084837 is a prime.

It is a super-2 number, since 2×42805085861² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42805085261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13779866 + ... + 13782971.

It is an arithmetic number, because the mean of its divisors is an integer number (10708162563).

Almost surely, 2^42805085861 is an apocalyptic number.

It is an amenable number.

42805085861 is a deficient number, since it is larger than the sum of its proper divisors (27564391).

42805085861 is a wasteful number, since it uses less digits than its factorization.

42805085861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27564390.

The product of its (nonzero) digits is 614400, while the sum is 47.

The spelling of 42805085861 in words is "forty-two billion, eight hundred five million, eighty-five thousand, eight hundred sixty-one".