1981628 has 24 divisors (see below), whose sum is σ = 3916080. Its totient is φ = 869120.

The previous prime is 1981627. The next prime is 1981631. The reversal of 1981628 is 8261891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981621) 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, 500 + ... + 2052.

It is an arithmetic number, because the mean of its divisors is an integer number (163170).

2^1981628 is an apocalyptic number.

It is an amenable number.

1981628 is a deficient number, since it is larger than the sum of its proper divisors (1934452).

1981628 is a wasteful number, since it uses less digits than its factorization.

1981628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1597 (or 1595 counting only the distinct ones).

The product of its digits is 6912, while the sum is 35.

The square root of 1981628 is about 1407.7030936955. The cubic root of 1981628 is about 125.6051298160.

The spelling of 1981628 in words is "one million, nine hundred eighty-one thousand, six hundred twenty-eight".