42138666 has 24 divisors (see below), whose sum is σ = 92554020. Its totient is φ = 13853376.

The previous prime is 42138661. The next prime is 42138683. The reversal of 42138666 is 66683124.

It can be written as a sum of positive squares in 2 ways, for example, as 40259025 + 1879641 = 6345^2 + 1371^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 42138666.

It is not an unprimeable number, because it can be changed into a prime (42138661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14721 + ... + 17348.

Almost surely, 2^42138666 is an apocalyptic number.

42138666 is an abundant number, since it is smaller than the sum of its proper divisors (50415354).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42138666 is a wasteful number, since it uses less digits than its factorization.

42138666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32150 (or 32147 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 42138666 is about 6491.4301968056. The cubic root of 42138666 is about 347.9847892678.

The spelling of 42138666 in words is "forty-two million, one hundred thirty-eight thousand, six hundred sixty-six".