3999625 has 24 divisors (see below), whose sum is σ = 5815368. Its totient is φ = 2738400.

The previous prime is 3999623. The next prime is 3999629. The reversal of 3999625 is 5269993.

3999625 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 480249 + 3519376 = 693^2 + 1876^2 .

It is not a de Polignac number, because 3999625 - 2¹ = 3999623 is a prime.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3999623) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 5799 + ... + 6451.

It is an arithmetic number, because the mean of its divisors is an integer number (242307).

Almost surely, 2^3999625 is an apocalyptic number.

3999625 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

3999625 is a deficient number, since it is larger than the sum of its proper divisors (1815743).

3999625 is an equidigital number, since it uses as much as digits as its factorization.

3999625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682 (or 665 counting only the distinct ones).

The product of its digits is 131220, while the sum is 43.

The square root of 3999625 is about 1999.9062478026. The cubic root of 3999625 is about 158.7351444135.

It can be divided in two parts, 3999 and 625, that added together give a square (4624 = 68²).

The spelling of 3999625 in words is "three million, nine hundred ninety-nine thousand, six hundred twenty-five".