42491638 has 32 divisors (see below), whose sum is σ = 79165440. Its totient is φ = 16692480.

The previous prime is 42491597. The next prime is 42491689. The reversal of 42491638 is 83619424.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 42491597 and 42491606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5670 + ... + 10822.

It is an arithmetic number, because the mean of its divisors is an integer number (2473920).

Almost surely, 2^42491638 is an apocalyptic number.

42491638 is the 4123-rd heptagonal number.

42491638 is a deficient number, since it is larger than the sum of its proper divisors (36673802).

42491638 is a wasteful number, since it uses less digits than its factorization.

42491638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5212.

The product of its digits is 41472, while the sum is 37.

The square root of 42491638 is about 6518.5610375297. The cubic root of 42491638 is about 348.9537134533.

The spelling of 42491638 in words is "forty-two million, four hundred ninety-one thousand, six hundred thirty-eight".