42087917 has 4 divisors (see below), whose sum is σ = 42179676. Its totient is φ = 41996160.

The previous prime is 42087911. The next prime is 42087919. The reversal of 42087917 is 71978024.

42087917 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.

It can be written as a sum of positive squares in 2 ways, for example, as 17147881 + 24940036 = 4141^2 + 4994^2 .

It is a cyclic number.

It is not a de Polignac number, because 42087917 - 2⁴ = 42087901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42087911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45188 + ... + 46109.

It is an arithmetic number, because the mean of its divisors is an integer number (10544919).

Almost surely, 2^42087917 is an apocalyptic number.

It is an amenable number.

42087917 is a deficient number, since it is larger than the sum of its proper divisors (91759).

42087917 is an equidigital number, since it uses as much as digits as its factorization.

42087917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91758.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 42087917 is about 6487.5200963080. The cubic root of 42087917 is about 347.8450365897.

The spelling of 42087917 in words is "forty-two million, eighty-seven thousand, nine hundred seventeen".