42166665 has 48 divisors (see below), whose sum is σ = 76317696. Its totient is φ = 21513600.

The previous prime is 42166627. The next prime is 42166669. The reversal of 42166665 is 56666124.

It is a happy number.

It is not a de Polignac number, because 42166665 - 2¹⁸ = 41904521 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

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 in 47 ways as a sum of consecutive naturals, for example, 232875 + ... + 233055.

It is an arithmetic number, because the mean of its divisors is an integer number (1589952).

Almost surely, 2^42166665 is an apocalyptic number.

42166665 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

42166665 is a deficient number, since it is larger than the sum of its proper divisors (34151031).

42166665 is a wasteful number, since it uses less digits than its factorization.

42166665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 387 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 42166665 is about 6493.5864512610. The cubic root of 42166665 is about 348.0618449340.

The spelling of 42166665 in words is "forty-two million, one hundred sixty-six thousand, six hundred sixty-five".