42166666 has 4 divisors (see below), whose sum is σ = 63250002. Its totient is φ = 21083332.

The previous prime is 42166627. The next prime is 42166669. The reversal of 42166666 is 66666124.

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., 41977441 + 189225 = 6479^2 + 435^2 .

42166666 is a modest number, since divided by 6666 gives 4216 as remainder.

It is not an unprimeable number, because it can be changed into a prime (42166669) by changing a digit.

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, 10541665 + ... + 10541668.

Almost surely, 2^42166666 is an apocalyptic number.

42166666 is a deficient number, since it is larger than the sum of its proper divisors (21083336).

42166666 is a wasteful number, since it uses less digits than its factorization.

42166666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21083335.

The product of its digits is 62208, while the sum is 37.

The square root of 42166666 is about 6493.5865282600. The cubic root of 42166666 is about 348.0618476855.

The spelling of 42166666 in words is "forty-two million, one hundred sixty-six thousand, six hundred sixty-six".