40638665 has 8 divisors (see below), whose sum is σ = 49077960. Its totient is φ = 32303232.

The previous prime is 40638629. The next prime is 40638673. The reversal of 40638665 is 56683604.

It can be written as a sum of positive squares in 4 ways, for example, as 2458624 + 38180041 = 1568^2 + 6179^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 40638665 - 2⁶ = 40638601 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25100 + ... + 26669.

It is an arithmetic number, because the mean of its divisors is an integer number (6134745).

Almost surely, 2^40638665 is an apocalyptic number.

It is an amenable number.

40638665 is a deficient number, since it is larger than the sum of its proper divisors (8439295).

40638665 is a wasteful number, since it uses less digits than its factorization.

40638665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51931.

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 40638665 is about 6374.8462726563. The cubic root of 40638665 is about 343.8057566857.

The spelling of 40638665 in words is "forty million, six hundred thirty-eight thousand, six hundred sixty-five".