42100805 has 8 divisors (see below), whose sum is σ = 50611992. Its totient is φ = 33619968.

The previous prime is 42100771. The next prime is 42100811. The reversal of 42100805 is 50800124.

It can be written as a sum of positive squares in 4 ways, for example, as 7219969 + 34880836 = 2687^2 + 5906^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42100805 - 2⁸ = 42100549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4412 + ... + 10181.

It is an arithmetic number, because the mean of its divisors is an integer number (6326499).

Almost surely, 2^42100805 is an apocalyptic number.

It is an amenable number.

42100805 is a deficient number, since it is larger than the sum of its proper divisors (8511187).

42100805 is a wasteful number, since it uses less digits than its factorization.

42100805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15175.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 42100805 is about 6488.5133119999. The cubic root of 42100805 is about 347.8805382224.

Adding to 42100805 its reverse (50800124), we get a palindrome (92900929).

The spelling of 42100805 in words is "forty-two million, one hundred thousand, eight hundred five".