40221666 has 36 divisors (see below), whose sum is σ = 90289602. Its totient is φ = 12940032.

The previous prime is 40221661. The next prime is 40221667. The reversal of 40221666 is 66612204.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 36905625 + 3316041 = 6075^2 + 1821^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40221661) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 13810 + ... + 16466.

Almost surely, 2^40221666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40221666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45144801).

40221666 is an abundant number, since it is smaller than the sum of its proper divisors (50067936).

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

40221666 is a wasteful number, since it uses less digits than its factorization.

40221666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2723 (or 2691 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 40221666 is about 6342.0553450754. The cubic root of 40221666 is about 342.6257651693.

The spelling of 40221666 in words is "forty million, two hundred twenty-one thousand, six hundred sixty-six".