1809825 has 24 divisors (see below), whose sum is σ = 3050400. Its totient is φ = 946560.

The previous prime is 1809823. The next prime is 1809833. The reversal of 1809825 is 5289081.

It is a happy number.

It is not a de Polignac number, because 1809825 - 2¹ = 1809823 is a prime.

It is an Ulam number.

1809825 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1809823) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4221 + ... + 4629.

It is an arithmetic number, because the mean of its divisors is an integer number (127100).

2^1809825 is an apocalyptic number.

1809825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1809825 is a deficient number, since it is larger than the sum of its proper divisors (1240575).

1809825 is a wasteful number, since it uses less digits than its factorization.

1809825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 476 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 1809825 is about 1345.2973648974. The cubic root of 1809825 is about 121.8649630130.

The spelling of 1809825 in words is "one million, eight hundred nine thousand, eight hundred twenty-five".