42638866 has 4 divisors (see below), whose sum is σ = 63958302. Its totient is φ = 21319432.

The previous prime is 42638821. The next prime is 42638879. The reversal of 42638866 is 66883624.

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., 42627841 + 11025 = 6529^2 + 105^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10659715 + ... + 10659718.

Almost surely, 2^42638866 is an apocalyptic number.

42638866 is a deficient number, since it is larger than the sum of its proper divisors (21319436).

42638866 is a wasteful number, since it uses less digits than its factorization.

42638866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21319435.

The product of its digits is 331776, while the sum is 43.

The square root of 42638866 is about 6529.8442554168. The cubic root of 42638866 is about 349.3562752821.

The spelling of 42638866 in words is "forty-two million, six hundred thirty-eight thousand, eight hundred sixty-six".