1815825 has 48 divisors (see below), whose sum is σ = 3428352. Its totient is φ = 840000.

The previous prime is 1815823. The next prime is 1815839. The reversal of 1815825 is 5285181.

It is not a de Polignac number, because 1815825 - 2¹ = 1815823 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1815792 and 1815801.

It is not an unprimeable number, because it can be changed into a prime (1815823) 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 47 ways as a sum of consecutive naturals, for example, 25540 + ... + 25610.

It is an arithmetic number, because the mean of its divisors is an integer number (71424).

2^1815825 is an apocalyptic number.

1815825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1815825 is a deficient number, since it is larger than the sum of its proper divisors (1612527).

1815825 is a wasteful number, since it uses less digits than its factorization.

1815825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 121 counting only the distinct ones).

The product of its digits is 3200, while the sum is 30.

The square root of 1815825 is about 1347.5255099626. The cubic root of 1815825 is about 121.9994849033. Note that the first 3 decimals are identical.

It can be divided in two parts, 181 and 5825, that added together give a palindrome (6006).

The spelling of 1815825 in words is "one million, eight hundred fifteen thousand, eight hundred twenty-five".