1881621 has 12 divisors (see below), whose sum is σ = 3106272. Its totient is φ = 1075176.

The previous prime is 1881619. The next prime is 1881631. The reversal of 1881621 is 1261881.

It is not a de Polignac number, because 1881621 - 2¹ = 1881619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1881601) 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 11 ways as a sum of consecutive naturals, for example, 14871 + ... + 14996.

It is an arithmetic number, because the mean of its divisors is an integer number (258856).

2^1881621 is an apocalyptic number.

It is an amenable number.

1881621 is a deficient number, since it is larger than the sum of its proper divisors (1224651).

1881621 is a wasteful number, since it uses less digits than its factorization.

1881621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29880 (or 29877 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

The square root of 1881621 is about 1371.7219105927. The cubic root of 1881621 is about 123.4555780071.

The spelling of 1881621 in words is "one million, eight hundred eighty-one thousand, six hundred twenty-one".