1881813 has 4 divisors (see below), whose sum is σ = 2509088. Its totient is φ = 1254540.

The previous prime is 1881811. The next prime is 1881821. The reversal of 1881813 is 3181881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1881813 - 2¹ = 1881811 is a prime.

It is a D-number.

It is a Duffinian number.

1881813 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1881811) 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 3 ways as a sum of consecutive naturals, for example, 313633 + ... + 313638.

It is an arithmetic number, because the mean of its divisors is an integer number (627272).

2^1881813 is an apocalyptic number.

It is an amenable number.

1881813 is a deficient number, since it is larger than the sum of its proper divisors (627275).

1881813 is an equidigital number, since it uses as much as digits as its factorization.

1881813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627274.

The product of its digits is 1536, while the sum is 30.

The square root of 1881813 is about 1371.7918938381. The cubic root of 1881813 is about 123.4597769867.

The spelling of 1881813 in words is "one million, eight hundred eighty-one thousand, eight hundred thirteen".