42878535237661 has 4 divisors (see below), whose sum is σ = 44357105418300. Its totient is φ = 41399965057024.

The previous prime is 42878535237647. The next prime is 42878535237667. The reversal of 42878535237661 is 16673253587824.

It is a happy number.

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 29176137432036 + 13702397805625 = 5401494^2 + 3701675^2 .

It is a cyclic number.

It is not a de Polignac number, because 42878535237661 - 2⁷ = 42878535237533 is a prime.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42878535237667) 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, 739285090276 + ... + 739285090333.

It is an arithmetic number, because the mean of its divisors is an integer number (11089276354575).

Almost surely, 2^{42878535237661} is an apocalyptic number.

It is an amenable number.

42878535237661 is a deficient number, since it is larger than the sum of its proper divisors (1478570180639).

42878535237661 is a wasteful number, since it uses less digits than its factorization.

42878535237661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1478570180638.

The product of its digits is 406425600, while the sum is 67.

The spelling of 42878535237661 in words is "forty-two trillion, eight hundred seventy-eight billion, five hundred thirty-five million, two hundred thirty-seven thousand, six hundred sixty-one".