40640666 has 8 divisors (see below), whose sum is σ = 66502944. Its totient is φ = 18473020.

The previous prime is 40640657. The next prime is 40640669. The reversal of 40640666 is 66604604.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (40640669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 923630 + ... + 923673.

It is an arithmetic number, because the mean of its divisors is an integer number (8312868).

Almost surely, 2^40640666 is an apocalyptic number.

40640666 is a deficient number, since it is larger than the sum of its proper divisors (25862278).

40640666 is a wasteful number, since it uses less digits than its factorization.

40640666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1847316.

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

The square root of 40640666 is about 6375.0032156855. The cubic root of 40640666 is about 343.8113994566.

The spelling of 40640666 in words is "forty million, six hundred forty thousand, six hundred sixty-six".