4000661505 has 24 divisors (see below), whose sum is σ = 7173602280. Its totient is φ = 2060110080.

The previous prime is 4000661453. The next prime is 4000661513. The reversal of 4000661505 is 5051660004.

It is a happy number.

4000661505 is a `hidden beast` number, since 40 + 0 + 0 + 6 + 615 + 0 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 838623681 + 3162037824 = 28959^2 + 56232^2 .

It is not a de Polignac number, because 4000661505 - 2¹¹ = 4000659457 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1531516 + ... + 1534125.

It is an arithmetic number, because the mean of its divisors is an integer number (298900095).

Almost surely, 2^4000661505 is an apocalyptic number.

4000661505 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

4000661505 is a deficient number, since it is larger than the sum of its proper divisors (3172940775).

4000661505 is a wasteful number, since it uses less digits than its factorization.

4000661505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3065681 (or 3065678 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 4000661505 is about 63250.7826433792. The cubic root of 4000661505 is about 1587.4885532892.

The spelling of 4000661505 in words is "four billion, six hundred sixty-one thousand, five hundred five".