4000985 has 16 divisors (see below), whose sum is σ = 5095440. Its totient is φ = 3010560.

The previous prime is 4000979. The next prime is 4000987. The reversal of 4000985 is 5890004.

4000985 = T₈₆ + T₈₇ + ... + T₂₉₀.

It can be written as a sum of positive squares in 8 ways, for example, as 692224 + 3308761 = 832^2 + 1819^2 .

It is a de Polignac number, because none of the positive numbers 2^k-4000985 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4000987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5609 + ... + 6281.

It is an arithmetic number, because the mean of its divisors is an integer number (318465).

Almost surely, 2^4000985 is an apocalyptic number.

It is an amenable number.

4000985 is a deficient number, since it is larger than the sum of its proper divisors (1094455).

4000985 is a wasteful number, since it uses less digits than its factorization.

4000985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 4000985 is about 2000.2462348421. The cubic root of 4000985 is about 158.7531340444.

Adding to 4000985 its reverse (5890004), we get a palindrome (9890989).

The spelling of 4000985 in words is "four million, nine hundred eighty-five", and thus it is an aban number.