42431666 has 4 divisors (see below), whose sum is σ = 63647502. Its totient is φ = 21215832.

The previous prime is 42431663. The next prime is 42431713. The reversal of 42431666 is 66613424.

42431666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 22762441 + 19669225 = 4771^2 + 4435^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42431663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10607915 + ... + 10607918.

Almost surely, 2^42431666 is an apocalyptic number.

42431666 is a deficient number, since it is larger than the sum of its proper divisors (21215836).

42431666 is a wasteful number, since it uses less digits than its factorization.

42431666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21215835.

The product of its digits is 20736, while the sum is 32.

The square root of 42431666 is about 6513.9593182641. The cubic root of 42431666 is about 348.7894669774.

The spelling of 42431666 in words is "forty-two million, four hundred thirty-one thousand, six hundred sixty-six".