42666640 has 40 divisors (see below), whose sum is σ = 99656568. Its totient is φ = 16988160.

The previous prime is 42666629. The next prime is 42666641. The reversal of 42666640 is 4666624.

It can be written as a sum of positive squares in 4 ways, for example, as 22127616 + 20539024 = 4704^2 + 4532^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 42666596 and 42666605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42666641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18174 + ... + 20386.

Almost surely, 2^42666640 is an apocalyptic number.

42666640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

42666640 is an abundant number, since it is smaller than the sum of its proper divisors (56989928).

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

42666640 is a wasteful number, since it uses less digits than its factorization.

42666640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2467 (or 2461 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 42666640 is about 6531.9706061800. The cubic root of 42666640 is about 349.4321130961.

The spelling of 42666640 in words is "forty-two million, six hundred sixty-six thousand, six hundred forty".