42668991 has 16 divisors (see below), whose sum is σ = 63360000. Its totient is φ = 28380024.

The previous prime is 42668959. The next prime is 42668993. The reversal of 42668991 is 19986624.

It is a happy number.

It is not a de Polignac number, because 42668991 - 2⁵ = 42668959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42668993) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11890 + ... + 15056.

It is an arithmetic number, because the mean of its divisors is an integer number (3960000).

Almost surely, 2^42668991 is an apocalyptic number.

42668991 is a deficient number, since it is larger than the sum of its proper divisors (20691009).

42668991 is a wasteful number, since it uses less digits than its factorization.

42668991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3675 (or 3669 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 42668991 is about 6532.1505647068. The cubic root of 42668991 is about 349.4385310674.

The spelling of 42668991 in words is "forty-two million, six hundred sixty-eight thousand, nine hundred ninety-one".