42090842 has 4 divisors (see below), whose sum is σ = 63136266. Its totient is φ = 21045420.

The previous prime is 42090821. The next prime is 42090857. The reversal of 42090842 is 24809024.

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

It can be written as a sum of positive squares in only one way, i.e., 30591961 + 11498881 = 5531^2 + 3391^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10522709 + ... + 10522712.

Almost surely, 2^42090842 is an apocalyptic number.

42090842 is a deficient number, since it is larger than the sum of its proper divisors (21045424).

42090842 is a wasteful number, since it uses less digits than its factorization.

42090842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21045423.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 42090842 is about 6487.7455252191. The cubic root of 42090842 is about 347.8530945093.

Adding to 42090842 its reverse (24809024), we get a palindrome (66899866).

The spelling of 42090842 in words is "forty-two million, ninety thousand, eight hundred forty-two".