42129090665 has 4 divisors (see below), whose sum is σ = 50554908804. Its totient is φ = 33703272528.

The previous prime is 42129090631. The next prime is 42129090673. The reversal of 42129090665 is 56609092124.

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 28443834409 + 13685256256 = 168653^2 + 116984^2 .

It is a cyclic number.

It is not a de Polignac number, because 42129090665 - 2¹⁶ = 42129025129 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 4212909062 + ... + 4212909071.

It is an arithmetic number, because the mean of its divisors is an integer number (12638727201).

Almost surely, 2^42129090665 is an apocalyptic number.

It is an amenable number.

42129090665 is a deficient number, since it is larger than the sum of its proper divisors (8425818139).

42129090665 is an equidigital number, since it uses as much as digits as its factorization.

42129090665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8425818138.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 42129090665 in words is "forty-two billion, one hundred twenty-nine million, ninety thousand, six hundred sixty-five".