1813520 has 20 divisors (see below), whose sum is σ = 4216620. Its totient is φ = 725376.

The previous prime is 1813517. The next prime is 1813523. The reversal of 1813520 is 253181.

It is an interprime number because it is at equal distance from previous prime (1813517) and next prime (1813523).

It can be written as a sum of positive squares in 2 ways, for example, as 1317904 + 495616 = 1148^2 + 704^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1813492 and 1813501.

It is not an unprimeable number, because it can be changed into a prime (1813523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11255 + ... + 11414.

It is an arithmetic number, because the mean of its divisors is an integer number (210831).

2^1813520 is an apocalyptic number.

1813520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1813520 is an abundant number, since it is smaller than the sum of its proper divisors (2403100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1813520 is a wasteful number, since it uses less digits than its factorization.

1813520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22682 (or 22676 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1813520 is about 1346.6699669927. The cubic root of 1813520 is about 121.9478411812.

The spelling of 1813520 in words is "one million, eight hundred thirteen thousand, five hundred twenty".