1980640 has 24 divisors (see below), whose sum is σ = 4679640. Its totient is φ = 792192.

The previous prime is 1980637. The next prime is 1980659. The reversal of 1980640 is 460891.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 1980599 and 1980608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6030 + ... + 6349.

It is an arithmetic number, because the mean of its divisors is an integer number (194985).

2^1980640 is an apocalyptic number.

1980640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1980640 is an abundant number, since it is smaller than the sum of its proper divisors (2699000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1980640 is a wasteful number, since it uses less digits than its factorization.

1980640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12394 (or 12386 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 1980640 is about 1407.3521236705. The cubic root of 1980640 is about 125.5842516125.

The spelling of 1980640 in words is "one million, nine hundred eighty thousand, six hundred forty".