40001665 has 16 divisors (see below), whose sum is σ = 53228736. Its totient is φ = 28612800.

The previous prime is 40001657. The next prime is 40001711. The reversal of 40001665 is 56610004.

It is not a de Polignac number, because 40001665 - 2³ = 40001657 is a prime.

40001665 is a modest number, since divided by 1665 gives 40 as remainder.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2607 + ... + 9316.

It is an arithmetic number, because the mean of its divisors is an integer number (3326796).

Almost surely, 2^40001665 is an apocalyptic number.

It is an amenable number.

40001665 is a deficient number, since it is larger than the sum of its proper divisors (13227071).

40001665 is a wasteful number, since it uses less digits than its factorization.

40001665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12000.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 40001665 is about 6324.6869487746. The cubic root of 40001665 is about 341.9999344528. Note that the first 4 decimals are identical.

Adding to 40001665 its reverse (56610004), we get a palindrome (96611669).

It can be divided in two parts, 4000 and 1665, that added together give a palindrome (5665).

The spelling of 40001665 in words is "forty million, one thousand, six hundred sixty-five".