4001605 has 8 divisors (see below), whose sum is σ = 4815864. Its totient is φ = 3192000.

The previous prime is 4001603. The next prime is 4001611. The reversal of 4001605 is 5061004.

It can be written as a sum of positive squares in 4 ways, for example, as 311364 + 3690241 = 558^2 + 1921^2 .

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

It is not a de Polignac number, because 4001605 - 2¹ = 4001603 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4001603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1155 + ... + 3055.

It is an arithmetic number, because the mean of its divisors is an integer number (601983).

Almost surely, 2^4001605 is an apocalyptic number.

It is an amenable number.

4001605 is a deficient number, since it is larger than the sum of its proper divisors (814259).

4001605 is a wasteful number, since it uses less digits than its factorization.

4001605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2327.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 4001605 is about 2000.4012097577. The cubic root of 4001605 is about 158.7613338468.

Adding to 4001605 its reverse (5061004), we get a palindrome (9062609).

The spelling of 4001605 in words is "four million, one thousand, six hundred five".