1881405 has 12 divisors (see below), whose sum is σ = 3261180. Its totient is φ = 1003392.

The previous prime is 1881403. The next prime is 1881419. The reversal of 1881405 is 5041881.

It can be written as a sum of positive squares in 2 ways, for example, as 622521 + 1258884 = 789^2 + 1122^2 .

It is not a de Polignac number, because 1881405 - 2¹ = 1881403 is a prime.

1881405 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1881401) 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 11 ways as a sum of consecutive naturals, for example, 20860 + ... + 20949.

It is an arithmetic number, because the mean of its divisors is an integer number (271765).

2^1881405 is an apocalyptic number.

1881405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1881405 is a deficient number, since it is larger than the sum of its proper divisors (1379775).

1881405 is a wasteful number, since it uses less digits than its factorization.

1881405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41820 (or 41817 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 1881405 is about 1371.6431751735. The cubic root of 1881405 is about 123.4508538135.

The spelling of 1881405 in words is "one million, eight hundred eighty-one thousand, four hundred five".