42639538 has 4 divisors (see below), whose sum is σ = 63959310. Its totient is φ = 21319768.

The previous prime is 42639529. The next prime is 42639559. The reversal of 42639538 is 83593624.

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., 23164969 + 19474569 = 4813^2 + 4413^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 42639538.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10659883 + ... + 10659886.

Almost surely, 2^42639538 is an apocalyptic number.

42639538 is a deficient number, since it is larger than the sum of its proper divisors (21319772).

42639538 is a wasteful number, since it uses less digits than its factorization.

42639538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21319771.

The product of its digits is 155520, while the sum is 40.

The square root of 42639538 is about 6529.8957112652. The cubic root of 42639538 is about 349.3581105887.

The spelling of 42639538 in words is "forty-two million, six hundred thirty-nine thousand, five hundred thirty-eight".