1980644 has 6 divisors (see below), whose sum is σ = 3466134. Its totient is φ = 990320.

The previous prime is 1980637. The next prime is 1980659. The reversal of 1980644 is 4460891.

It can be written as a sum of positive squares in only one way, i.e., 1849600 + 131044 = 1360^2 + 362^2 .

It is a super-4 number, since 4×1980644⁴ (a number of 26 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1980644.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 247577 + ... + 247584.

It is an arithmetic number, because the mean of its divisors is an integer number (577689).

2^1980644 is an apocalyptic number.

It is an amenable number.

1980644 is a deficient number, since it is larger than the sum of its proper divisors (1485490).

1980644 is a wasteful number, since it uses less digits than its factorization.

1980644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495165 (or 495163 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1980644 is about 1407.3535447783. The cubic root of 1980644 is about 125.5843361536.

The spelling of 1980644 in words is "one million, nine hundred eighty thousand, six hundred forty-four".