1881820 has 24 divisors (see below), whose sum is σ = 4060224. Its totient is φ = 732096.

The previous prime is 1881811. The next prime is 1881821. The reversal of 1881820 is 281881.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1881821) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 532 + ... + 2011.

It is an arithmetic number, because the mean of its divisors is an integer number (169176).

2^1881820 is an apocalyptic number.

1881820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1881820 is an abundant number, since it is smaller than the sum of its proper divisors (2178404).

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

1881820 is a wasteful number, since it uses less digits than its factorization.

1881820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2589 (or 2587 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 28.

The square root of 1881820 is about 1371.7944452432. The cubic root of 1881820 is about 123.4599300691.

It can be divided in two parts, 1881 and 820, that added together give a triangular number (2701 = T₇₃).

The spelling of 1881820 in words is "one million, eight hundred eighty-one thousand, eight hundred twenty".