40001905 has 8 divisors (see below), whose sum is σ = 48268584. Its totient is φ = 31824000.

The previous prime is 40001893. The next prime is 40001939. The reversal of 40001905 is 50910004.

It can be written as a sum of positive squares in 4 ways, for example, as 1648656 + 38353249 = 1284^2 + 6193^2 .

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

It is not a de Polignac number, because 40001905 - 2⁷ = 40001777 is a prime.

It is a super-3 number, since 3×40001905³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

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, 21196 + ... + 23005.

It is an arithmetic number, because the mean of its divisors is an integer number (6033573).

Almost surely, 2^40001905 is an apocalyptic number.

It is an amenable number.

40001905 is a deficient number, since it is larger than the sum of its proper divisors (8266679).

40001905 is a wasteful number, since it uses less digits than its factorization.

40001905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44387.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 40001905 is about 6324.7059220172. The cubic root of 40001905 is about 342.0006184228. Note that the first 3 decimals are identical.

Adding to 40001905 its reverse (50910004), we get a palindrome (90911909).

The spelling of 40001905 in words is "forty million, one thousand, nine hundred five".