1815980 has 48 divisors (see below), whose sum is σ = 4112640. Its totient is φ = 672000.

The previous prime is 1815977. The next prime is 1816007. The reversal of 1815980 is 895181.

It is a happy number.

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17930 + ... + 18030.

It is an arithmetic number, because the mean of its divisors is an integer number (85680).

2^1815980 is an apocalyptic number.

1815980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1815980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2056320).

1815980 is an abundant number, since it is smaller than the sum of its proper divisors (2296660).

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

1815980 is a wasteful number, since it uses less digits than its factorization.

1815980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 32.

The square root of 1815980 is about 1347.5830215612. The cubic root of 1815980 is about 122.0029561229.

The spelling of 1815980 in words is "one million, eight hundred fifteen thousand, nine hundred eighty".