40081666 has 4 divisors (see below), whose sum is σ = 60122502. Its totient is φ = 20040832.

The previous prime is 40081651. The next prime is 40081669. The reversal of 40081666 is 66618004.

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., 29975625 + 10106041 = 5475^2 + 3179^2 .

It is not an unprimeable number, because it can be changed into a prime (40081669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10020415 + ... + 10020418.

Almost surely, 2^40081666 is an apocalyptic number.

40081666 is a deficient number, since it is larger than the sum of its proper divisors (20040836).

40081666 is a wasteful number, since it uses less digits than its factorization.

40081666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20040835.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 40081666 is about 6331.0082925234. The cubic root of 40081666 is about 342.2277759464.

The spelling of 40081666 in words is "forty million, eighty-one thousand, six hundred sixty-six".