1800520 has 16 divisors (see below), whose sum is σ = 4051260. Its totient is φ = 720192.

The previous prime is 1800499. The next prime is 1800529. The reversal of 1800520 is 250081.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1552516 + 248004 = 1246^2 + 498^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1800494 and 1800503.

It is not an unprimeable number, because it can be changed into a prime (1800529) 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 3 ways as a sum of consecutive naturals, for example, 22467 + ... + 22546.

2^1800520 is an apocalyptic number.

1800520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1800520 is an abundant number, since it is smaller than the sum of its proper divisors (2250740).

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

1800520 is a wasteful number, since it uses less digits than its factorization.

1800520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45024 (or 45020 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 1800520 is about 1341.8345650638. The cubic root of 1800520 is about 121.6557526542.

The spelling of 1800520 in words is "one million, eight hundred thousand, five hundred twenty".