1968640 has 40 divisors (see below), whose sum is σ = 4726260. Its totient is φ = 786432.

The previous prime is 1968613. The next prime is 1968641. The reversal of 1968640 is 468691.

It can be written as a sum of positive squares in 2 ways, for example, as 1937664 + 30976 = 1392^2 + 176^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 1968596 and 1968605.

It is not an unprimeable number, because it can be changed into a prime (1968641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2176 + ... + 2944.

2^1968640 is an apocalyptic number.

1968640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1968640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2363130).

1968640 is an abundant number, since it is smaller than the sum of its proper divisors (2757620).

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

1968640 is an frugal number, since it uses more digits than its factorization.

1968640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792 (or 776 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 1968640 is about 1403.0823211772. The cubic root of 1968640 is about 125.3301140967.

It can be divided in two parts, 196 and 8640, that added together give a square (8836 = 94²).

The spelling of 1968640 in words is "one million, nine hundred sixty-eight thousand, six hundred forty".