1881890 has 8 divisors (see below), whose sum is σ = 3387420. Its totient is φ = 752752.

The previous prime is 1881889. The next prime is 1881899. The reversal of 1881890 is 981881.

It can be written as a sum of positive squares in 2 ways, for example, as 1739761 + 142129 = 1319^2 + 377^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1881890.

It is not an unprimeable number, because it can be changed into a prime (1881899) 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, 94085 + ... + 94104.

2^1881890 is an apocalyptic number.

1881890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1881890 is a deficient number, since it is larger than the sum of its proper divisors (1505530).

1881890 is a wasteful number, since it uses less digits than its factorization.

1881890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188196.

The product of its (nonzero) digits is 4608, while the sum is 35.

The square root of 1881890 is about 1371.8199590325. The cubic root of 1881890 is about 123.4614608723.

Subtracting from 1881890 its reverse (981881), we obtain a palindrome (900009).

The spelling of 1881890 in words is "one million, eight hundred eighty-one thousand, eight hundred ninety".